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数据库操作类真的没有必要自己去写,因为成熟的类库真的非常完善了,拿来直接用就好,省时省力。

本文就为大家介绍微软官方的程序PetShop4.0中的SqlHelper类,先来做一下简单的介绍,PetShop是一个范例,微软用它来展示.Net企业系统开发的能力。

那SqlHelper中封装了哪些方法呢?

里面的函数一堆,常用的就那几个,无非就是增删改查嘛,来看下几种常用的函数:

1.ExecuteNonQuery 执行增删改
2.ExecuteReader 执行查询
3.ExecuteScalar 返回首行首列

使用方法介绍

Web.config配置

<connectionStrings>
	<add name="ConnectionString" connectionString="server=127.0.0.1;uid=sa;pwd=ok;database=PetShop;Max Pool Size =512; Min Pool Size=0; Connection Lifetime = 300;packet size=1000;" providerName="System.Data.SqlClient" />
</connectionStrings>

调用函数的写法

sql = "UPDATE Student set Name = @Name WHERE Id = @Id";
SqlHelper.ExecuteNonQuery(CommandType.Text, sql, new SqlParameter[]{
 new SqlParameter("@Name", name),
 new SqlParameter("@Id", id)
});

这样调用就比较简化,而且比较灵活

源码呈上

/// <summary>
  /// The SqlHelper class is intended to encapsulate high performance, 
  /// scalable best practices for common uses of SqlClient.
  /// </summary>
  public abstract class SqlHelper
  {

    //数据库连接字符串
    public static readonly string ConnectionString = ConfigurationManager.ConnectionStrings["SQLConnString"].ConnectionString;

    #region 私有函数和方法

    /// <summary>
    /// This method is used to attach array of SqlParameters to a SqlCommand.
    /// 
    /// This method will assign a value of DbNull to any parameter with a direction of
    /// InputOutput and a value of null. 
    /// 
    /// This behavior will prevent default values from being used, but
    /// this will be the less common case than an intended pure output parameter (derived as InputOutput)
    /// where the user provided no input value.
    /// </summary>
    /// <param name="command">The command to which the parameters will be added</param>
    /// <param name="commandParameters">An array of SqlParameters to be added to command</param>
    private static void AttachParameters(SqlCommand command, SqlParameter[] commandParameters)
    {
      if (command == null) throw new ArgumentNullException("command");
      if (commandParameters != null)
      {
        foreach (SqlParameter p in commandParameters)
        {
          if (p != null)
          {
            // Check for derived output value with no value assigned
            if ((p.Direction == ParameterDirection.InputOutput ||
              p.Direction == ParameterDirection.Input) &&
              (p.Value == null))
            {
              p.Value = DBNull.Value;
            }
            command.Parameters.Add(p);
          }
        }
      }
    }

    /// <summary>
    /// This method assigns dataRow column values to an array of SqlParameters
    /// </summary>
    /// <param name="commandParameters">Array of SqlParameters to be assigned values</param>
    /// <param name="dataRow">The dataRow used to hold the stored procedure's parameter values</param>
    private static void AssignParameterValues(SqlParameter[] commandParameters, DataRow dataRow)
    {
      if ((commandParameters == null) || (dataRow == null))
      {
        // Do nothing if we get no data
        return;
      }

      int i = 0;
      // Set the parameters values
      foreach (SqlParameter commandParameter in commandParameters)
      {
        // Check the parameter name
        if (commandParameter.ParameterName == null ||
          commandParameter.ParameterName.Length <= 1)
          throw new Exception(
            string.Format(
              "Please provide a valid parameter name on the parameter #{0}, the ParameterName property has the following value: '{1}'.",
              i, commandParameter.ParameterName));
        if (dataRow.Table.Columns.IndexOf(commandParameter.ParameterName.Substring(1)) != -1)
          commandParameter.Value = dataRow[commandParameter.ParameterName.Substring(1)];
        i++;
      }
    }

    /// <summary>
    /// This method assigns an array of values to an array of SqlParameters
    /// </summary>
    /// <param name="commandParameters">Array of SqlParameters to be assigned values</param>
    /// <param name="parameterValues">Array of objects holding the values to be assigned</param>
    private static void AssignParameterValues(SqlParameter[] commandParameters, object[] parameterValues)
    {
      if ((commandParameters == null) || (parameterValues == null))
      {
        // Do nothing if we get no data
        return;
      }

      // We must have the same number of values as we pave parameters to put them in
      if (commandParameters.Length != parameterValues.Length)
      {
        throw new ArgumentException("Parameter count does not match Parameter Value count.");
      }

      // Iterate through the SqlParameters, assigning the values from the corresponding position in the 
      // value array
      for (int i = 0, j = commandParameters.Length; i < j; i++)
      {
        // If the current array value derives from IDbDataParameter, then assign its Value property
        if (parameterValues[i] is IDbDataParameter)
        {
          IDbDataParameter paramInstance = (IDbDataParameter)parameterValues[i];
          if (paramInstance.Value == null)
          {
            commandParameters[i].Value = DBNull.Value;
          }
          else
          {
            commandParameters[i].Value = paramInstance.Value;
          }
        }
        else if (parameterValues[i] == null)
        {
          commandParameters[i].Value = DBNull.Value;
        }
        else
        {
          commandParameters[i].Value = parameterValues[i];
        }
      }
    }

    /// <summary>
    /// This method opens (if necessary) and assigns a connection, transaction, command type and parameters 
    /// to the provided command
    /// </summary>
    /// <param name="command">The SqlCommand to be prepared</param>
    /// <param name="connection">A valid SqlConnection, on which to execute this command</param>
    /// <param name="transaction">A valid SqlTransaction, or 'null'</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command</param>
    /// <param name="commandParameters">An array of SqlParameters to be associated with the command or 'null' if no parameters are required</param>
    /// <param name="mustCloseConnection"><c>true</c> if the connection was opened by the method, otherwose is false.</param>
    private static void PrepareCommand(SqlCommand command, SqlConnection connection, SqlTransaction transaction, CommandType commandType, string commandText, SqlParameter[] commandParameters, out bool mustCloseConnection)
    {
      if (command == null) throw new ArgumentNullException("command");
      if (commandText == null || commandText.Length == 0) throw new ArgumentNullException("commandText");

      // If the provided connection is not open, we will open it
      if (connection.State != ConnectionState.Open)
      {
        mustCloseConnection = true;
        connection.Open();
      }
      else
      {
        mustCloseConnection = false;
      }

      // Associate the connection with the command
      command.Connection = connection;

      // Set the command text (stored procedure name or SQL statement)
      command.CommandText = commandText;

      // If we were provided a transaction, assign it
      if (transaction != null)
      {
        if (transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
        command.Transaction = transaction;
      }

      // Set the command type
      command.CommandType = commandType;

      // Attach the command parameters if they are provided
      if (commandParameters != null)
      {
        AttachParameters(command, commandParameters);
      }
      return;
    }

    #endregion private utility methods & constructors

    #region ExecuteNonQuery

    public static int ExecuteNonQuery(CommandType cmdType, string cmdText)
    {
      return ExecuteNonQuery(ConnectionString, cmdType, cmdText);
    }

    public static int ExecuteNonQuery(CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
    {
      return ExecuteNonQuery(ConnectionString, cmdType, cmdText, commandParameters);
    }

    /// <summary>
    /// Execute a SqlCommand (that returns no resultset and takes no parameters) against the database specified in 
    /// the connection string
    /// </summary>
    /// <remarks>
    /// e.g.: 
    /// int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders");
    /// </remarks>
    /// <param name="connectionString">A valid connection string for a SqlConnection</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command</param>
    /// <returns>An int representing the number of rows affected by the command</returns>
    public static int ExecuteNonQuery(string connectionString, CommandType commandType, string commandText)
    {
      // Pass through the call providing null for the set of SqlParameters
      return ExecuteNonQuery(connectionString, commandType, commandText, (SqlParameter[])null);
    }

    /// <summary>
    /// Execute a SqlCommand (that returns no resultset) against the database specified in the connection string 
    /// using the provided parameters
    /// </summary>
    /// <remarks>
    /// e.g.: 
    /// int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
    /// </remarks>
    /// <param name="connectionString">A valid connection string for a SqlConnection</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command</param>
    /// <param name="commandParameters">An array of SqlParamters used to execute the command</param>
    /// <returns>An int representing the number of rows affected by the command</returns>
    public static int ExecuteNonQuery(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
    {
      if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");

      // Create & open a SqlConnection, and dispose of it after we are done
      using (SqlConnection connection = new SqlConnection(connectionString))
      {
        connection.Open();

        // Call the overload that takes a connection in place of the connection string
        return ExecuteNonQuery(connection, commandType, commandText, commandParameters);
      }
    }

    /// <summary>
    /// Execute a stored procedure via a SqlCommand (that returns no resultset) against the database specified in 
    /// the connection string using the provided parameter values. This method will query the database to discover the parameters for the 
    /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
    /// </summary>
    /// <remarks>
    /// This method provides no access to output parameters or the stored procedure's return value parameter.
    /// 
    /// e.g.: 
    /// int result = ExecuteNonQuery(connString, "PublishOrders", 24, 36);
    /// </remarks>
    /// <param name="connectionString">A valid connection string for a SqlConnection</param>
    /// <param name="spName">The name of the stored prcedure</param>
    /// <param name="parameterValues">An array of objects to be assigned as the input values of the stored procedure</param>
    /// <returns>An int representing the number of rows affected by the command</returns>
    public static int ExecuteNonQuery(string connectionString, string spName, params object[] parameterValues)
    {
      if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
      if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

      // If we receive parameter values, we need to figure out where they go
      if ((parameterValues != null) && (parameterValues.Length > 0))
      {
        // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
        SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

        // Assign the provided values to these parameters based on parameter order
        AssignParameterValues(commandParameters, parameterValues);

        // Call the overload that takes an array of SqlParameters
        return ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName, commandParameters);
      }
      else
      {
        // Otherwise we can just call the SP without params
        return ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName);
      }
    }

    /// <summary>
    /// Execute a SqlCommand (that returns no resultset and takes no parameters) against the provided SqlConnection. 
    /// </summary>
    /// <remarks>
    /// e.g.: 
    /// int result = ExecuteNonQuery(conn, CommandType.StoredProcedure, "PublishOrders");
    /// </remarks>
    /// <param name="connection">A valid SqlConnection</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command</param>
    /// <returns>An int representing the number of rows affected by the command</returns>
    public static int ExecuteNonQuery(SqlConnection connection, CommandType commandType, string commandText)
    {
      // Pass through the call providing null for the set of SqlParameters
      return ExecuteNonQuery(connection, commandType, commandText, (SqlParameter[])null);
    }

    /// <summary>
    /// Execute a SqlCommand (that returns no resultset) against the specified SqlConnection 
    /// using the provided parameters.
    /// </summary>
    /// <remarks>
    /// e.g.: 
    /// int result = ExecuteNonQuery(conn, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
    /// </remarks>
    /// <param name="connection">A valid SqlConnection</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command</param>
    /// <param name="commandParameters">An array of SqlParamters used to execute the command</param>
    /// <returns>An int representing the number of rows affected by the command</returns>
    public static int ExecuteNonQuery(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
    {
      if (connection == null) throw new ArgumentNullException("connection");

      // Create a command and prepare it for execution
      SqlCommand cmd = new SqlCommand();
      bool mustCloseConnection = false;
      PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection);

      // Finally, execute the command
      int retval = cmd.ExecuteNonQuery();

      // Detach the SqlParameters from the command object, so they can be used again
      cmd.Parameters.Clear();
      if (mustCloseConnection)
        connection.Close();
      return retval;
    }

    /// <summary>
    /// Execute a stored procedure via a SqlCommand (that returns no resultset) against the specified SqlConnection 
    /// using the provided parameter values. This method will query the database to discover the parameters for the 
    /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
    /// </summary>
    /// <remarks>
    /// This method provides no access to output parameters or the stored procedure's return value parameter.
    /// 
    /// e.g.: 
    /// int result = ExecuteNonQuery(conn, "PublishOrders", 24, 36);
    /// </remarks>
    /// <param name="connection">A valid SqlConnection</param>
    /// <param name="spName">The name of the stored procedure</param>
    /// <param name="parameterValues">An array of objects to be assigned as the input values of the stored procedure</param>
    /// <returns>An int representing the number of rows affected by the command</returns>
    public static int ExecuteNonQuery(SqlConnection connection, string spName, params object[] parameterValues)
    {
      if (connection == null) throw new ArgumentNullException("connection");
      if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

      // If we receive parameter values, we need to figure out where they go
      if ((parameterValues != null) && (parameterValues.Length > 0))
      {
        // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
        SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

        // Assign the provided values to these parameters based on parameter order
        AssignParameterValues(commandParameters, parameterValues);

        // Call the overload that takes an array of SqlParameters
        return ExecuteNonQuery(connection, CommandType.StoredProcedure, spName, commandParameters);
      }
      else
      {
        // Otherwise we can just call the SP without params
        return ExecuteNonQuery(connection, CommandType.StoredProcedure, spName);
      }
    }

    /// <summary>
    /// Execute a SqlCommand (that returns no resultset and takes no parameters) against the provided SqlTransaction. 
    /// </summary>
    /// <remarks>
    /// e.g.: 
    /// int result = ExecuteNonQuery(trans, CommandType.StoredProcedure, "PublishOrders");
    /// </remarks>
    /// <param name="transaction">A valid SqlTransaction</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command</param>
    /// <returns>An int representing the number of rows affected by the command</returns>
    public static int ExecuteNonQuery(SqlTransaction transaction, CommandType commandType, string commandText)
    {
      // Pass through the call providing null for the set of SqlParameters
      return ExecuteNonQuery(transaction, commandType, commandText, (SqlParameter[])null);
    }

    /// <summary>
    /// Execute a SqlCommand (that returns no resultset) against the specified SqlTransaction
    /// using the provided parameters.
    /// </summary>
    /// <remarks>
    /// e.g.: 
    /// int result = ExecuteNonQuery(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
    /// </remarks>
    /// <param name="transaction">A valid SqlTransaction</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command</param>
    /// <param name="commandParameters">An array of SqlParamters used to execute the command</param>
    /// <returns>An int representing the number of rows affected by the command</returns>
    public static int ExecuteNonQuery(SqlTransaction transaction, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
    {
      if (transaction == null) throw new ArgumentNullException("transaction");
      if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");

      // Create a command and prepare it for execution
      SqlCommand cmd = new SqlCommand();
      bool mustCloseConnection = false;
      PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);

      // Finally, execute the command
      int retval = cmd.ExecuteNonQuery();

      // Detach the SqlParameters from the command object, so they can be used again
      cmd.Parameters.Clear();
      return retval;
    }

    /// <summary>
    /// Execute a stored procedure via a SqlCommand (that returns no resultset) against the specified 
    /// SqlTransaction using the provided parameter values. This method will query the database to discover the parameters for the 
    /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
    /// </summary>
    /// <remarks>
    /// This method provides no access to output parameters or the stored procedure's return value parameter.
    /// 
    /// e.g.: 
    /// int result = ExecuteNonQuery(conn, trans, "PublishOrders", 24, 36);
    /// </remarks>
    /// <param name="transaction">A valid SqlTransaction</param>
    /// <param name="spName">The name of the stored procedure</param>
    /// <param name="parameterValues">An array of objects to be assigned as the input values of the stored procedure</param>
    /// <returns>An int representing the number of rows affected by the command</returns>
    public static int ExecuteNonQuery(SqlTransaction transaction, string spName, params object[] parameterValues)
    {
      if (transaction == null) throw new ArgumentNullException("transaction");
      if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
      if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

      // If we receive parameter values, we need to figure out where they go
      if ((parameterValues != null) && (parameterValues.Length > 0))
      {
        // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
        SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

        // Assign the provided values to these parameters based on parameter order
        AssignParameterValues(commandParameters, parameterValues);

        // Call the overload that takes an array of SqlParameters
        return ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName, commandParameters);
      }
      else
      {
        // Otherwise we can just call the SP without params
        return ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName);
      }
    }

    #endregion ExecuteNonQuery

    #region ExecuteDataset

    public static DataSet ExecuteDataset(CommandType commandType, string commandText)
    {
      return ExecuteDataset(ConnectionString, commandType, commandText);
    }

    public static DataSet ExecuteDataset(CommandType commandType, string commandText, params SqlParameter[] commandParameters)
    {
      return ExecuteDataset(ConnectionString, commandType, commandText, commandParameters);
    }

    /// <summary>
    /// Execute a SqlCommand (that returns a resultset and takes no parameters) against the database specified in 
    /// the connection string. 
    /// </summary>
    /// <remarks>
    /// e.g.: 
    /// DataSet ds = ExecuteDataset(connString, CommandType.StoredProcedure, "GetOrders");
    /// </remarks>
    /// <param name="connectionString">A valid connection string for a SqlConnection</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command</param>
    /// <returns>A dataset containing the resultset generated by the command</returns>
    public static DataSet ExecuteDataset(string connectionString, CommandType commandType, string commandText)
    {
      // Pass through the call providing null for the set of SqlParameters
      return ExecuteDataset(connectionString, commandType, commandText, (SqlParameter[])null);
    }

    /// <summary>
    /// Execute a SqlCommand (that returns a resultset) against the database specified in the connection string 
    /// using the provided parameters.
    /// </summary>
    /// <remarks>
    /// e.g.: 
    /// DataSet ds = ExecuteDataset(connString, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
    /// </remarks>
    /// <param name="connectionString">A valid connection string for a SqlConnection</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command</param>
    /// <param name="commandParameters">An array of SqlParamters used to execute the command</param>
    /// <returns>A dataset containing the resultset generated by the command</returns>
    public static DataSet ExecuteDataset(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
    {
      if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");

      // Create & open a SqlConnection, and dispose of it after we are done
      using (SqlConnection connection = new SqlConnection(connectionString))
      {
        connection.Open();

        // Call the overload that takes a connection in place of the connection string
        return ExecuteDataset(connection, commandType, commandText, commandParameters);
      }
    }

    /// <summary>
    /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the database specified in 
    /// the connection string using the provided parameter values. This method will query the database to discover the parameters for the 
    /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
    /// </summary>
    /// <remarks>
    /// This method provides no access to output parameters or the stored procedure's return value parameter.
    /// 
    /// e.g.: 
    /// DataSet ds = ExecuteDataset(connString, "GetOrders", 24, 36);
    /// </remarks>
    /// <param name="connectionString">A valid connection string for a SqlConnection</param>
    /// <param name="spName">The name of the stored procedure</param>
    /// <param name="parameterValues">An array of objects to be assigned as the input values of the stored procedure</param>
    /// <returns>A dataset containing the resultset generated by the command</returns>
    public static DataSet ExecuteDataset(string connectionString, string spName, params object[] parameterValues)
    {
      if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
      if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

      // If we receive parameter values, we need to figure out where they go
      if ((parameterValues != null) && (parameterValues.Length > 0))
      {
        // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
        SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

        // Assign the provided values to these parameters based on parameter order
        AssignParameterValues(commandParameters, parameterValues);

        // Call the overload that takes an array of SqlParameters
        return ExecuteDataset(connectionString, CommandType.StoredProcedure, spName, commandParameters);
      }
      else
      {
        // Otherwise we can just call the SP without params
        return ExecuteDataset(connectionString, CommandType.StoredProcedure, spName);
      }
    }

    /// <summary>
    /// Execute a SqlCommand (that returns a resultset and takes no parameters) against the provided SqlConnection. 
    /// </summary>
    /// <remarks>
    /// e.g.: 
    /// DataSet ds = ExecuteDataset(conn, CommandType.StoredProcedure, "GetOrders");
    /// </remarks>
    /// <param name="connection">A valid SqlConnection</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command</param>
    /// <returns>A dataset containing the resultset generated by the command</returns>
    public static DataSet ExecuteDataset(SqlConnection connection, CommandType commandType, string commandText)
    {
      // Pass through the call providing null for the set of SqlParameters
      return ExecuteDataset(connection, commandType, commandText, (SqlParameter[])null);
    }

    /// <summary>
    /// Execute a SqlCommand (that returns a resultset) against the specified SqlConnection 
    /// using the provided parameters.
    /// </summary>
    /// <remarks>
    /// e.g.: 
    /// DataSet ds = ExecuteDataset(conn, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
    /// </remarks>
    /// <param name="connection">A valid SqlConnection</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command</param>
    /// <param name="commandParameters">An array of SqlParamters used to execute the command</param>
    /// <returns>A dataset containing the resultset generated by the command</returns>
    public static DataSet ExecuteDataset(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
    {
      if (connection == null) throw new ArgumentNullException("connection");

      // Create a command and prepare it for execution
      SqlCommand cmd = new SqlCommand();
      bool mustCloseConnection = false;
      PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection);

      // Create the DataAdapter & DataSet
      using (SqlDataAdapter da = new SqlDataAdapter(cmd))
      {
        DataSet ds = new DataSet();

        // Fill the DataSet using default values for DataTable names, etc
        da.Fill(ds);

        // Detach the SqlParameters from the command object, so they can be used again
        cmd.Parameters.Clear();

        if (mustCloseConnection)
          connection.Close();

        // Return the dataset
        return ds;
      }
    }

    /// <summary>
    /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the specified SqlConnection 
    /// using the provided parameter values. This method will query the database to discover the parameters for the 
    /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
    /// </summary>
    /// <remarks>
    /// This method provides no access to output parameters or the stored procedure's return value parameter.
    /// 
    /// e.g.: 
    /// DataSet ds = ExecuteDataset(conn, "GetOrders", 24, 36);
    /// </remarks>
    /// <param name="connection">A valid SqlConnection</param>
    /// <param name="spName">The name of the stored procedure</param>
    /// <param name="parameterValues">An array of objects to be assigned as the input values of the stored procedure</param>
    /// <returns>A dataset containing the resultset generated by the command</returns>
    public static DataSet ExecuteDataset(SqlConnection connection, string spName, params object[] parameterValues)
    {
      if (connection == null) throw new ArgumentNullException("connection");
      if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

      // If we receive parameter values, we need to figure out where they go
      if ((parameterValues != null) && (parameterValues.Length > 0))
      {
        // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
        SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

        // Assign the provided values to these parameters based on parameter order
        AssignParameterValues(commandParameters, parameterValues);

        // Call the overload that takes an array of SqlParameters
        return ExecuteDataset(connection, CommandType.StoredProcedure, spName, commandParameters);
      }
      else
      {
        // Otherwise we can just call the SP without params
        return ExecuteDataset(connection, CommandType.StoredProcedure, spName);
      }
    }

    /// <summary>
    /// Execute a SqlCommand (that returns a resultset and takes no parameters) against the provided SqlTransaction. 
    /// </summary>
    /// <remarks>
    /// e.g.: 
    /// DataSet ds = ExecuteDataset(trans, CommandType.StoredProcedure, "GetOrders");
    /// </remarks>
    /// <param name="transaction">A valid SqlTransaction</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command</param>
    /// <returns>A dataset containing the resultset generated by the command</returns>
    public static DataSet ExecuteDataset(SqlTransaction transaction, CommandType commandType, string commandText)
    {
      // Pass through the call providing null for the set of SqlParameters
      return ExecuteDataset(transaction, commandType, commandText, (SqlParameter[])null);
    }

    /// <summary>
    /// Execute a SqlCommand (that returns a resultset) against the specified SqlTransaction
    /// using the provided parameters.
    /// </summary>
    /// <remarks>
    /// e.g.: 
    /// DataSet ds = ExecuteDataset(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
    /// </remarks>
    /// <param name="transaction">A valid SqlTransaction</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command</param>
    /// <param name="commandParameters">An array of SqlParamters used to execute the command</param>
    /// <returns>A dataset containing the resultset generated by the command</returns>
    public static DataSet ExecuteDataset(SqlTransaction transaction, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
    {
      if (transaction == null) throw new ArgumentNullException("transaction");
      if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");

      // Create a command and prepare it for execution
      SqlCommand cmd = new SqlCommand();
      bool mustCloseConnection = false;
      PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);

      // Create the DataAdapter & DataSet
      using (SqlDataAdapter da = new SqlDataAdapter(cmd))
      {
        DataSet ds = new DataSet();

        // Fill the DataSet using default values for DataTable names, etc
        da.Fill(ds);

        // Detach the SqlParameters from the command object, so they can be used again
        cmd.Parameters.Clear();

        // Return the dataset
        return ds;
      }
    }

    /// <summary>
    /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the specified 
    /// SqlTransaction using the provided parameter values. This method will query the database to discover the parameters for the 
    /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
    /// </summary>
    /// <remarks>
    /// This method provides no access to output parameters or the stored procedure's return value parameter.
    /// 
    /// e.g.: 
    /// DataSet ds = ExecuteDataset(trans, "GetOrders", 24, 36);
    /// </remarks>
    /// <param name="transaction">A valid SqlTransaction</param>
    /// <param name="spName">The name of the stored procedure</param>
    /// <param name="parameterValues">An array of objects to be assigned as the input values of the stored procedure</param>
    /// <returns>A dataset containing the resultset generated by the command</returns>
    public static DataSet ExecuteDataset(SqlTransaction transaction, string spName, params object[] parameterValues)
    {
      if (transaction == null) throw new ArgumentNullException("transaction");
      if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
      if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

      // If we receive parameter values, we need to figure out where they go
      if ((parameterValues != null) && (parameterValues.Length > 0))
      {
        // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
        SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

        // Assign the provided values to these parameters based on parameter order
        AssignParameterValues(commandParameters, parameterValues);

        // Call the overload that takes an array of SqlParameters
        return ExecuteDataset(transaction, CommandType.StoredProcedure, spName, commandParameters);
      }
      else
      {
        // Otherwise we can just call the SP without params
        return ExecuteDataset(transaction, CommandType.StoredProcedure, spName);
      }
    }

    #endregion ExecuteDataset

    #region ExecuteReader

    /// <summary>
    /// This enum is used to indicate whether the connection was provided by the caller, or created by SqlHelper, so that
    /// we can set the appropriate CommandBehavior when calling ExecuteReader()
    /// </summary>
    private enum SqlConnectionOwnership
    {
      /// <summary>Connection is owned and managed by SqlHelper</summary>
      Internal,
      /// <summary>Connection is owned and managed by the caller</summary>
      External
    }

    public static SqlDataReader ExecuteReader(CommandType cmdType, string cmdText)
    {
      return ExecuteReader(ConnectionString, cmdType, cmdText);
    }

    public static SqlDataReader ExecuteReader(CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
    {
      return ExecuteReader(ConnectionString, cmdType, cmdText, commandParameters);
    }

    /// <summary>
    /// Create and prepare a SqlCommand, and call ExecuteReader with the appropriate CommandBehavior.
    /// </summary>
    /// <remarks>
    /// If we created and opened the connection, we want the connection to be closed when the DataReader is closed.
    /// 
    /// If the caller provided the connection, we want to leave it to them to manage.
    /// </remarks>
    /// <param name="connection">A valid SqlConnection, on which to execute this command</param>
    /// <param name="transaction">A valid SqlTransaction, or 'null'</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command</param>
    /// <param name="commandParameters">An array of SqlParameters to be associated with the command or 'null' if no parameters are required</param>
    /// <param name="connectionOwnership">Indicates whether the connection parameter was provided by the caller, or created by SqlHelper</param>
    /// <returns>SqlDataReader containing the results of the command</returns>
    private static SqlDataReader ExecuteReader(SqlConnection connection, SqlTransaction transaction, CommandType commandType, string commandText, SqlParameter[] commandParameters, SqlConnectionOwnership connectionOwnership)
    {
      if (connection == null) throw new ArgumentNullException("connection");

      bool mustCloseConnection = false;
      // Create a command and prepare it for execution
      SqlCommand cmd = new SqlCommand();
      try
      {
        PrepareCommand(cmd, connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);

        // Create a reader
        SqlDataReader dataReader;

        // Call ExecuteReader with the appropriate CommandBehavior
        if (connectionOwnership == SqlConnectionOwnership.External)
        {
          dataReader = cmd.ExecuteReader();
        }
        else
        {
          dataReader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
        }

        // Detach the SqlParameters from the command object, so they can be used again.
        // HACK: There is a problem here, the output parameter values are fletched 
        // when the reader is closed, so if the parameters are detached from the command
        // then the SqlReader can磘 set its values. 
        // When this happen, the parameters can磘 be used again in other command.
        bool canClear = true;
        foreach (SqlParameter commandParameter in cmd.Parameters)
        {
          if (commandParameter.Direction != ParameterDirection.Input)
            canClear = false;
        }

        if (canClear)
        {
          cmd.Parameters.Clear();
        }

        return dataReader;
      }
      catch
      {
        if (mustCloseConnection)
          connection.Close();
        throw;
      }
    }

    /// <summary>
    /// Execute a SqlCommand (that returns a resultset and takes no parameters) against the database specified in 
    /// the connection string. 
    /// </summary>
    /// <remarks>
    /// e.g.: 
    /// SqlDataReader dr = ExecuteReader(connString, CommandType.StoredProcedure, "GetOrders");
    /// </remarks>
    /// <param name="connectionString">A valid connection string for a SqlConnection</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command</param>
    /// <returns>A SqlDataReader containing the resultset generated by the command</returns>
    public static SqlDataReader ExecuteReader(string connectionString, CommandType commandType, string commandText)
    {
      // Pass through the call providing null for the set of SqlParameters
      return ExecuteReader(connectionString, commandType, commandText, (SqlParameter[])null);
    }

    /// <summary>
    /// Execute a SqlCommand (that returns a resultset) against the database specified in the connection string 
    /// using the provided parameters.
    /// </summary>
    /// <remarks>
    /// e.g.: 
    /// SqlDataReader dr = ExecuteReader(connString, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
    /// </remarks>
    /// <param name="connectionString">A valid connection string for a SqlConnection</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command</param>
    /// <param name="commandParameters">An array of SqlParamters used to execute the command</param>
    /// <returns>A SqlDataReader containing the resultset generated by the command</returns>
    public static SqlDataReader ExecuteReader(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
    {
      if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
      SqlConnection connection = null;
      try
      {
        connection = new SqlConnection(connectionString);
        connection.Open();

        // Call the private overload that takes an internally owned connection in place of the connection string
        return ExecuteReader(connection, null, commandType, commandText, commandParameters, SqlConnectionOwnership.Internal);
      }
      catch
      {
        // If we fail to return the SqlDatReader, we need to close the connection ourselves
        if (connection != null) connection.Close();
        throw;
      }

    }

    /// <summary>
    /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the database specified in 
    /// the connection string using the provided parameter values. This method will query the database to discover the parameters for the 
    /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
    /// </summary>
    /// <remarks>
    /// This method provides no access to output parameters or the stored procedure's return value parameter.
    /// 
    /// e.g.: 
    /// SqlDataReader dr = ExecuteReader(connString, "GetOrders", 24, 36);
    /// </remarks>
    /// <param name="connectionString">A valid connection string for a SqlConnection</param>
    /// <param name="spName">The name of the stored procedure</param>
    /// <param name="parameterValues">An array of objects to be assigned as the input values of the stored procedure</param>
    /// <returns>A SqlDataReader containing the resultset generated by the command</returns>
    public static SqlDataReader ExecuteReader(string connectionString, string spName, params object[] parameterValues)
    {
      if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
      if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

      // If we receive parameter values, we need to figure out where they go
      if ((parameterValues != null) && (parameterValues.Length > 0))
      {
        SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

        AssignParameterValues(commandParameters, parameterValues);

        return ExecuteReader(connectionString, CommandType.StoredProcedure, spName, commandParameters);
      }
      else
      {
        // Otherwise we can just call the SP without params
        return ExecuteReader(connectionString, CommandType.StoredProcedure, spName);
      }
    }

    /// <summary>
    /// Execute a SqlCommand (that returns a resultset and takes no parameters) against the provided SqlConnection. 
    /// </summary>
    /// <remarks>
    /// e.g.: 
    /// SqlDataReader dr = ExecuteReader(conn, CommandType.StoredProcedure, "GetOrders");
    /// </remarks>
    /// <param name="connection">A valid SqlConnection</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command</param>
    /// <returns>A SqlDataReader containing the resultset generated by the command</returns>
    public static SqlDataReader ExecuteReader(SqlConnection connection, CommandType commandType, string commandText)
    {
      // Pass through the call providing null for the set of SqlParameters
      return ExecuteReader(connection, commandType, commandText, (SqlParameter[])null);
    }

    /// <summary>
    /// Execute a SqlCommand (that returns a resultset) against the specified SqlConnection 
    /// using the provided parameters.
    /// </summary>
    /// <remarks>
    /// e.g.: 
    /// SqlDataReader dr = ExecuteReader(conn, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
    /// </remarks>
    /// <param name="connection">A valid SqlConnection</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command</param>
    /// <param name="commandParameters">An array of SqlParamters used to execute the command</param>
    /// <returns>A SqlDataReader containing the resultset generated by the command</returns>
    public static SqlDataReader ExecuteReader(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
    {
      // Pass through the call to the private overload using a null transaction value and an externally owned connection
      return ExecuteReader(connection, (SqlTransaction)null, commandType, commandText, commandParameters, SqlConnectionOwnership.External);
    }

    /// <summary>
    /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the specified SqlConnection 
    /// using the provided parameter values. This method will query the database to discover the parameters for the 
    /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
    /// </summary>
    /// <remarks>
    /// This method provides no access to output parameters or the stored procedure's return value parameter.
    /// 
    /// e.g.: 
    /// SqlDataReader dr = ExecuteReader(conn, "GetOrders", 24, 36);
    /// </remarks>
    /// <param name="connection">A valid SqlConnection</param>
    /// <param name="spName">The name of the stored procedure</param>
    /// <param name="parameterValues">An array of objects to be assigned as the input values of the stored procedure</param>
    /// <returns>A SqlDataReader containing the resultset generated by the command</returns>
    public static SqlDataReader ExecuteReader(SqlConnection connection, string spName, params object[] parameterValues)
    {
      if (connection == null) throw new ArgumentNullException("connection");
      if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

      // If we receive parameter values, we need to figure out where they go
      if ((parameterValues != null) && (parameterValues.Length > 0))
      {
        SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

        AssignParameterValues(commandParameters, parameterValues);

        return ExecuteReader(connection, CommandType.StoredProcedure, spName, commandParameters);
      }
      else
      {
        // Otherwise we can just call the SP without params
        return ExecuteReader(connection, CommandType.StoredProcedure, spName);
      }
    }

    /// <summary>
    /// Execute a SqlCommand (that returns a resultset and takes no parameters) against the provided SqlTransaction. 
    /// </summary>
    /// <remarks>
    /// e.g.: 
    /// SqlDataReader dr = ExecuteReader(trans, CommandType.StoredProcedure, "GetOrders");
    /// </remarks>
    /// <param name="transaction">A valid SqlTransaction</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command</param>
    /// <returns>A SqlDataReader containing the resultset generated by the command</returns>
    public static SqlDataReader ExecuteReader(SqlTransaction transaction, CommandType commandType, string commandText)
    {
      // Pass through the call providing null for the set of SqlParameters
      return ExecuteReader(transaction, commandType, commandText, (SqlParameter[])null);
    }

    /// <summary>
    /// Execute a SqlCommand (that returns a resultset) against the specified SqlTransaction
    /// using the provided parameters.
    /// </summary>
    /// <remarks>
    /// e.g.: 
    ///  SqlDataReader dr = ExecuteReader(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
    /// </remarks>
    /// <param name="transaction">A valid SqlTransaction</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command</param>
    /// <param name="commandParameters">An array of SqlParamters used to execute the command</param>
    /// <returns>A SqlDataReader containing the resultset generated by the command</returns>
    public static SqlDataReader ExecuteReader(SqlTransaction transaction, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
    {
      if (transaction == null) throw new ArgumentNullException("transaction");
      if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");

      // Pass through to private overload, indicating that the connection is owned by the caller
      return ExecuteReader(transaction.Connection, transaction, commandType, commandText, commandParameters, SqlConnectionOwnership.External);
    }

    /// <summary>
    /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the specified
    /// SqlTransaction using the provided parameter values. This method will query the database to discover the parameters for the 
    /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
    /// </summary>
    /// <remarks>
    /// This method provides no access to output parameters or the stored procedure's return value parameter.
    /// 
    /// e.g.: 
    /// SqlDataReader dr = ExecuteReader(trans, "GetOrders", 24, 36);
    /// </remarks>
    /// <param name="transaction">A valid SqlTransaction</param>
    /// <param name="spName">The name of the stored procedure</param>
    /// <param name="parameterValues">An array of objects to be assigned as the input values of the stored procedure</param>
    /// <returns>A SqlDataReader containing the resultset generated by the command</returns>
    public static SqlDataReader ExecuteReader(SqlTransaction transaction, string spName, params object[] parameterValues)
    {
      if (transaction == null) throw new ArgumentNullException("transaction");
      if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
      if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

      // If we receive parameter values, we need to figure out where they go
      if ((parameterValues != null) && (parameterValues.Length > 0))
      {
        SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

        AssignParameterValues(commandParameters, parameterValues);

        return ExecuteReader(transaction, CommandType.StoredProcedure, spName, commandParameters);
      }
      else
      {
        // Otherwise we can just call the SP without params
        return ExecuteReader(transaction, CommandType.StoredProcedure, spName);
      }
    }

    #endregion ExecuteReader

    #region ExecuteScalar

    public static object ExecuteScalar(CommandType cmdType, string cmdText)
    {
      return ExecuteScalar(ConnectionString, cmdType, cmdText);
    }

    public static object ExecuteScalar(CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
    {
      return ExecuteScalar(ConnectionString, cmdType, cmdText, commandParameters);
    }

    /// <summary>
    /// Execute a SqlCommand (that returns a 1x1 resultset and takes no parameters) against the database specified in 
    /// the connection string. 
    /// </summary>
    /// <remarks>
    /// e.g.: 
    /// int orderCount = (int)ExecuteScalar(connString, CommandType.StoredProcedure, "GetOrderCount");
    /// </remarks>
    /// <param name="connectionString">A valid connection string for a SqlConnection</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command</param>
    /// <returns>An object containing the value in the 1x1 resultset generated by the command</returns>
    public static object ExecuteScalar(string connectionString, CommandType commandType, string commandText)
    {
      // Pass through the call providing null for the set of SqlParameters
      return ExecuteScalar(connectionString, commandType, commandText, (SqlParameter[])null);
    }

    /// <summary>
    /// Execute a SqlCommand (that returns a 1x1 resultset) against the database specified in the connection string 
    /// using the provided parameters.
    /// </summary>
    /// <remarks>
    /// e.g.: 
    /// int orderCount = (int)ExecuteScalar(connString, CommandType.StoredProcedure, "GetOrderCount", new SqlParameter("@prodid", 24));
    /// </remarks>
    /// <param name="connectionString">A valid connection string for a SqlConnection</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command</param>
    /// <param name="commandParameters">An array of SqlParamters used to execute the command</param>
    /// <returns>An object containing the value in the 1x1 resultset generated by the command</returns>
    public static object ExecuteScalar(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
    {
      if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
      // Create & open a SqlConnection, and dispose of it after we are done
      using (SqlConnection connection = new SqlConnection(connectionString))
      {
        connection.Open();

        // Call the overload that takes a connection in place of the connection string
        return ExecuteScalar(connection, commandType, commandText, commandParameters);
      }
    }

    /// <summary>
    /// Execute a stored procedure via a SqlCommand (that returns a 1x1 resultset) against the database specified in 
    /// the connection string using the provided parameter values. This method will query the database to discover the parameters for the 
    /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
    /// </summary>
    /// <remarks>
    /// This method provides no access to output parameters or the stored procedure's return value parameter.
    /// 
    /// e.g.: 
    /// int orderCount = (int)ExecuteScalar(connString, "GetOrderCount", 24, 36);
    /// </remarks>
    /// <param name="connectionString">A valid connection string for a SqlConnection</param>
    /// <param name="spName">The name of the stored procedure</param>
    /// <param name="parameterValues">An array of objects to be assigned as the input values of the stored procedure</param>
    /// <returns>An object containing the value in the 1x1 resultset generated by the command</returns>
    public static object ExecuteScalar(string connectionString, string spName, params object[] parameterValues)
    {
      if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
      if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

      // If we receive parameter values, we need to figure out where they go
      if ((parameterValues != null) && (parameterValues.Length > 0))
      {
        // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
        SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

        // Assign the provided values to these parameters based on parameter order
        AssignParameterValues(commandParameters, parameterValues);

        // Call the overload that takes an array of SqlParameters
        return ExecuteScalar(connectionString, CommandType.StoredProcedure, spName, commandParameters);
      }
      else
      {
        // Otherwise we can just call the SP without params
        return ExecuteScalar(connectionString, CommandType.StoredProcedure, spName);
      }
    }

    /// <summary>
    /// Execute a SqlCommand (that returns a 1x1 resultset and takes no parameters) against the provided SqlConnection. 
    /// </summary>
    /// <remarks>
    /// e.g.: 
    /// int orderCount = (int)ExecuteScalar(conn, CommandType.StoredProcedure, "GetOrderCount");
    /// </remarks>
    /// <param name="connection">A valid SqlConnection</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command</param>
    /// <returns>An object containing the value in the 1x1 resultset generated by the command</returns>
    public static object ExecuteScalar(SqlConnection connection, CommandType commandType, string commandText)
    {
      // Pass through the call providing null for the set of SqlParameters
      return ExecuteScalar(connection, commandType, commandText, (SqlParameter[])null);
    }

    /// <summary>
    /// Execute a SqlCommand (that returns a 1x1 resultset) against the specified SqlConnection 
    /// using the provided parameters.
    /// </summary>
    /// <remarks>
    /// e.g.: 
    /// int orderCount = (int)ExecuteScalar(conn, CommandType.StoredProcedure, "GetOrderCount", new SqlParameter("@prodid", 24));
    /// </remarks>
    /// <param name="connection">A valid SqlConnection</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command</param>
    /// <param name="commandParameters">An array of SqlParamters used to execute the command</param>
    /// <returns>An object containing the value in the 1x1 resultset generated by the command</returns>
    public static object ExecuteScalar(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
    {
      if (connection == null) throw new ArgumentNullException("connection");

      // Create a command and prepare it for execution
      SqlCommand cmd = new SqlCommand();

      bool mustCloseConnection = false;
      PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection);

      // Execute the command & return the results
      object retval = cmd.ExecuteScalar();

      // Detach the SqlParameters from the command object, so they can be used again
      cmd.Parameters.Clear();

      if (mustCloseConnection)
        connection.Close();

      return retval;
    }

    /// <summary>
    /// Execute a stored procedure via a SqlCommand (that returns a 1x1 resultset) against the specified SqlConnection 
    /// using the provided parameter values. This method will query the database to discover the parameters for the 
    /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
    /// </summary>
    /// <remarks>
    /// This method provides no access to output parameters or the stored procedure's return value parameter.
    /// 
    /// e.g.: 
    /// int orderCount = (int)ExecuteScalar(conn, "GetOrderCount", 24, 36);
    /// </remarks>
    /// <param name="connection">A valid SqlConnection</param>
    /// <param name="spName">The name of the stored procedure</param>
    /// <param name="parameterValues">An array of objects to be assigned as the input values of the stored procedure</param>
    /// <returns>An object containing the value in the 1x1 resultset generated by the command</returns>
    public static object ExecuteScalar(SqlConnection connection, string spName, params object[] parameterValues)
    {
      if (connection == null) throw new ArgumentNullException("connection");
      if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

      // If we receive parameter values, we need to figure out where they go
      if ((parameterValues != null) && (parameterValues.Length > 0))
      {
        // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
        SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

        // Assign the provided values to these parameters based on parameter order
        AssignParameterValues(commandParameters, parameterValues);

        // Call the overload that takes an array of SqlParameters
        return ExecuteScalar(connection, CommandType.StoredProcedure, spName, commandParameters);
      }
      else
      {
        // Otherwise we can just call the SP without params
        return ExecuteScalar(connection, CommandType.StoredProcedure, spName);
      }
    }

    /// <summary>
    /// Execute a SqlCommand (that returns a 1x1 resultset and takes no parameters) against the provided SqlTransaction. 
    /// </summary>
    /// <remarks>
    /// e.g.: 
    /// int orderCount = (int)ExecuteScalar(trans, CommandType.StoredProcedure, "GetOrderCount");
    /// </remarks>
    /// <param name="transaction">A valid SqlTransaction</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command</param>
    /// <returns>An object containing the value in the 1x1 resultset generated by the command</returns>
    public static object ExecuteScalar(SqlTransaction transaction, CommandType commandType, string commandText)
    {
      // Pass through the call providing null for the set of SqlParameters
      return ExecuteScalar(transaction, commandType, commandText, (SqlParameter[])null);
    }

    /// <summary>
    /// Execute a SqlCommand (that returns a 1x1 resultset) against the specified SqlTransaction
    /// using the provided parameters.
    /// </summary>
    /// <remarks>
    /// e.g.: 
    /// int orderCount = (int)ExecuteScalar(trans, CommandType.StoredProcedure, "GetOrderCount", new SqlParameter("@prodid", 24));
    /// </remarks>
    /// <param name="transaction">A valid SqlTransaction</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command</param>
    /// <param name="commandParameters">An array of SqlParamters used to execute the command</param>
    /// <returns>An object containing the value in the 1x1 resultset generated by the command</returns>
    public static object ExecuteScalar(SqlTransaction transaction, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
    {
      if (transaction == null) throw new ArgumentNullException("transaction");
      if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");

      // Create a command and prepare it for execution
      SqlCommand cmd = new SqlCommand();
      bool mustCloseConnection = false;
      PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);

      // Execute the command & return the results
      object retval = cmd.ExecuteScalar();

      // Detach the SqlParameters from the command object, so they can be used again
      cmd.Parameters.Clear();
      return retval;
    }

    /// <summary>
    /// Execute a stored procedure via a SqlCommand (that returns a 1x1 resultset) against the specified
    /// SqlTransaction using the provided parameter values. This method will query the database to discover the parameters for the 
    /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
    /// </summary>
    /// <remarks>
    /// This method provides no access to output parameters or the stored procedure's return value parameter.
    /// 
    /// e.g.: 
    /// int orderCount = (int)ExecuteScalar(trans, "GetOrderCount", 24, 36);
    /// </remarks>
    /// <param name="transaction">A valid SqlTransaction</param>
    /// <param name="spName">The name of the stored procedure</param>
    /// <param name="parameterValues">An array of objects to be assigned as the input values of the stored procedure</param>
    /// <returns>An object containing the value in the 1x1 resultset generated by the command</returns>
    public static object ExecuteScalar(SqlTransaction transaction, string spName, params object[] parameterValues)
    {
      if (transaction == null) throw new ArgumentNullException("transaction");
      if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
      if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

      // If we receive parameter values, we need to figure out where they go
      if ((parameterValues != null) && (parameterValues.Length > 0))
      {
        // PPull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
        SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

        // Assign the provided values to these parameters based on parameter order
        AssignParameterValues(commandParameters, parameterValues);

        // Call the overload that takes an array of SqlParameters
        return ExecuteScalar(transaction, CommandType.StoredProcedure, spName, commandParameters);
      }
      else
      {
        // Otherwise we can just call the SP without params
        return ExecuteScalar(transaction, CommandType.StoredProcedure, spName);
      }
    }

    #endregion ExecuteScalar

    #region ExecuteXmlReader

    /// <summary>
    /// Execute a SqlCommand (that returns a resultset and takes no parameters) against the provided SqlConnection. 
    /// </summary>
    /// <remarks>
    /// e.g.: 
    /// XmlReader r = ExecuteXmlReader(conn, CommandType.StoredProcedure, "GetOrders");
    /// </remarks>
    /// <param name="connection">A valid SqlConnection</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command using "FOR XML AUTO"</param>
    /// <returns>An XmlReader containing the resultset generated by the command</returns>
    public static XmlReader ExecuteXmlReader(SqlConnection connection, CommandType commandType, string commandText)
    {
      // Pass through the call providing null for the set of SqlParameters
      return ExecuteXmlReader(connection, commandType, commandText, (SqlParameter[])null);
    }

    /// <summary>
    /// Execute a SqlCommand (that returns a resultset) against the specified SqlConnection 
    /// using the provided parameters.
    /// </summary>
    /// <remarks>
    /// e.g.: 
    /// XmlReader r = ExecuteXmlReader(conn, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
    /// </remarks>
    /// <param name="connection">A valid SqlConnection</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command using "FOR XML AUTO"</param>
    /// <param name="commandParameters">An array of SqlParamters used to execute the command</param>
    /// <returns>An XmlReader containing the resultset generated by the command</returns>
    public static XmlReader ExecuteXmlReader(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
    {
      if (connection == null) throw new ArgumentNullException("connection");

      bool mustCloseConnection = false;
      // Create a command and prepare it for execution
      SqlCommand cmd = new SqlCommand();
      try
      {
        PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection);

        // Create the DataAdapter & DataSet
        XmlReader retval = cmd.ExecuteXmlReader();

        // Detach the SqlParameters from the command object, so they can be used again
        cmd.Parameters.Clear();

        return retval;
      }
      catch
      {
        if (mustCloseConnection)
          connection.Close();
        throw;
      }
    }

    /// <summary>
    /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the specified SqlConnection 
    /// using the provided parameter values. This method will query the database to discover the parameters for the 
    /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
    /// </summary>
    /// <remarks>
    /// This method provides no access to output parameters or the stored procedure's return value parameter.
    /// 
    /// e.g.: 
    /// XmlReader r = ExecuteXmlReader(conn, "GetOrders", 24, 36);
    /// </remarks>
    /// <param name="connection">A valid SqlConnection</param>
    /// <param name="spName">The name of the stored procedure using "FOR XML AUTO"</param>
    /// <param name="parameterValues">An array of objects to be assigned as the input values of the stored procedure</param>
    /// <returns>An XmlReader containing the resultset generated by the command</returns>
    public static XmlReader ExecuteXmlReader(SqlConnection connection, string spName, params object[] parameterValues)
    {
      if (connection == null) throw new ArgumentNullException("connection");
      if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

      // If we receive parameter values, we need to figure out where they go
      if ((parameterValues != null) && (parameterValues.Length > 0))
      {
        // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
        SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

        // Assign the provided values to these parameters based on parameter order
        AssignParameterValues(commandParameters, parameterValues);

        // Call the overload that takes an array of SqlParameters
        return ExecuteXmlReader(connection, CommandType.StoredProcedure, spName, commandParameters);
      }
      else
      {
        // Otherwise we can just call the SP without params
        return ExecuteXmlReader(connection, CommandType.StoredProcedure, spName);
      }
    }

    /// <summary>
    /// Execute a SqlCommand (that returns a resultset and takes no parameters) against the provided SqlTransaction. 
    /// </summary>
    /// <remarks>
    /// e.g.: 
    /// XmlReader r = ExecuteXmlReader(trans, CommandType.StoredProcedure, "GetOrders");
    /// </remarks>
    /// <param name="transaction">A valid SqlTransaction</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command using "FOR XML AUTO"</param>
    /// <returns>An XmlReader containing the resultset generated by the command</returns>
    public static XmlReader ExecuteXmlReader(SqlTransaction transaction, CommandType commandType, string commandText)
    {
      // Pass through the call providing null for the set of SqlParameters
      return ExecuteXmlReader(transaction, commandType, commandText, (SqlParameter[])null);
    }

    /// <summary>
    /// Execute a SqlCommand (that returns a resultset) against the specified SqlTransaction
    /// using the provided parameters.
    /// </summary>
    /// <remarks>
    /// e.g.: 
    /// XmlReader r = ExecuteXmlReader(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
    /// </remarks>
    /// <param name="transaction">A valid SqlTransaction</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command using "FOR XML AUTO"</param>
    /// <param name="commandParameters">An array of SqlParamters used to execute the command</param>
    /// <returns>An XmlReader containing the resultset generated by the command</returns>
    public static XmlReader ExecuteXmlReader(SqlTransaction transaction, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
    {
      if (transaction == null) throw new ArgumentNullException("transaction");
      if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");

      // Create a command and prepare it for execution
      SqlCommand cmd = new SqlCommand();
      bool mustCloseConnection = false;
      PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);

      // Create the DataAdapter & DataSet
      XmlReader retval = cmd.ExecuteXmlReader();

      // Detach the SqlParameters from the command object, so they can be used again
      cmd.Parameters.Clear();
      return retval;
    }

    /// <summary>
    /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the specified 
    /// SqlTransaction using the provided parameter values. This method will query the database to discover the parameters for the 
    /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
    /// </summary>
    /// <remarks>
    /// This method provides no access to output parameters or the stored procedure's return value parameter.
    /// 
    /// e.g.: 
    /// XmlReader r = ExecuteXmlReader(trans, "GetOrders", 24, 36);
    /// </remarks>
    /// <param name="transaction">A valid SqlTransaction</param>
    /// <param name="spName">The name of the stored procedure</param>
    /// <param name="parameterValues">An array of objects to be assigned as the input values of the stored procedure</param>
    /// <returns>A dataset containing the resultset generated by the command</returns>
    public static XmlReader ExecuteXmlReader(SqlTransaction transaction, string spName, params object[] parameterValues)
    {
      if (transaction == null) throw new ArgumentNullException("transaction");
      if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
      if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

      // If we receive parameter values, we need to figure out where they go
      if ((parameterValues != null) && (parameterValues.Length > 0))
      {
        // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
        SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

        // Assign the provided values to these parameters based on parameter order
        AssignParameterValues(commandParameters, parameterValues);

        // Call the overload that takes an array of SqlParameters
        return ExecuteXmlReader(transaction, CommandType.StoredProcedure, spName, commandParameters);
      }
      else
      {
        // Otherwise we can just call the SP without params
        return ExecuteXmlReader(transaction, CommandType.StoredProcedure, spName);
      }
    }

    #endregion ExecuteXmlReader

    #region FillDataset
    /// <summary>
    /// Execute a SqlCommand (that returns a resultset and takes no parameters) against the database specified in 
    /// the connection string. 
    /// </summary>
    /// <remarks>
    /// e.g.: 
    /// FillDataset(connString, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"});
    /// </remarks>
    /// <param name="connectionString">A valid connection string for a SqlConnection</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command</param>
    /// <param name="dataSet">A dataset wich will contain the resultset generated by the command</param>
    /// <param name="tableNames">This array will be used to create table mappings allowing the DataTables to be referenced
    /// by a user defined name (probably the actual table name)</param>
    public static void FillDataset(string connectionString, CommandType commandType, string commandText, DataSet dataSet, string[] tableNames)
    {
      if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
      if (dataSet == null) throw new ArgumentNullException("dataSet");

      // Create & open a SqlConnection, and dispose of it after we are done
      using (SqlConnection connection = new SqlConnection(connectionString))
      {
        connection.Open();

        // Call the overload that takes a connection in place of the connection string
        FillDataset(connection, commandType, commandText, dataSet, tableNames);
      }
    }

    /// <summary>
    /// Execute a SqlCommand (that returns a resultset) against the database specified in the connection string 
    /// using the provided parameters.
    /// </summary>
    /// <remarks>
    /// e.g.: 
    /// FillDataset(connString, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, new SqlParameter("@prodid", 24));
    /// </remarks>
    /// <param name="connectionString">A valid connection string for a SqlConnection</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command</param>
    /// <param name="commandParameters">An array of SqlParamters used to execute the command</param>
    /// <param name="dataSet">A dataset wich will contain the resultset generated by the command</param>
    /// <param name="tableNames">This array will be used to create table mappings allowing the DataTables to be referenced
    /// by a user defined name (probably the actual table name)
    /// </param>
    public static void FillDataset(string connectionString, CommandType commandType,
      string commandText, DataSet dataSet, string[] tableNames,
      params SqlParameter[] commandParameters)
    {
      if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
      if (dataSet == null) throw new ArgumentNullException("dataSet");
      // Create & open a SqlConnection, and dispose of it after we are done
      using (SqlConnection connection = new SqlConnection(connectionString))
      {
        connection.Open();

        // Call the overload that takes a connection in place of the connection string
        FillDataset(connection, commandType, commandText, dataSet, tableNames, commandParameters);
      }
    }

    /// <summary>
    /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the database specified in 
    /// the connection string using the provided parameter values. This method will query the database to discover the parameters for the 
    /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
    /// </summary>
    /// <remarks>
    /// This method provides no access to output parameters or the stored procedure's return value parameter.
    /// 
    /// e.g.: 
    /// FillDataset(connString, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, 24);
    /// </remarks>
    /// <param name="connectionString">A valid connection string for a SqlConnection</param>
    /// <param name="spName">The name of the stored procedure</param>
    /// <param name="dataSet">A dataset wich will contain the resultset generated by the command</param>
    /// <param name="tableNames">This array will be used to create table mappings allowing the DataTables to be referenced
    /// by a user defined name (probably the actual table name)
    /// </param>  
    /// <param name="parameterValues">An array of objects to be assigned as the input values of the stored procedure</param>
    public static void FillDataset(string connectionString, string spName,
      DataSet dataSet, string[] tableNames,
      params object[] parameterValues)
    {
      if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
      if (dataSet == null) throw new ArgumentNullException("dataSet");
      // Create & open a SqlConnection, and dispose of it after we are done
      using (SqlConnection connection = new SqlConnection(connectionString))
      {
        connection.Open();

        // Call the overload that takes a connection in place of the connection string
        FillDataset(connection, spName, dataSet, tableNames, parameterValues);
      }
    }

    /// <summary>
    /// Execute a SqlCommand (that returns a resultset and takes no parameters) against the provided SqlConnection. 
    /// </summary>
    /// <remarks>
    /// e.g.: 
    /// FillDataset(conn, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"});
    /// </remarks>
    /// <param name="connection">A valid SqlConnection</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command</param>
    /// <param name="dataSet">A dataset wich will contain the resultset generated by the command</param>
    /// <param name="tableNames">This array will be used to create table mappings allowing the DataTables to be referenced
    /// by a user defined name (probably the actual table name)
    /// </param>  
    public static void FillDataset(SqlConnection connection, CommandType commandType,
      string commandText, DataSet dataSet, string[] tableNames)
    {
      FillDataset(connection, commandType, commandText, dataSet, tableNames, null);
    }

    /// <summary>
    /// Execute a SqlCommand (that returns a resultset) against the specified SqlConnection 
    /// using the provided parameters.
    /// </summary>
    /// <remarks>
    /// e.g.: 
    /// FillDataset(conn, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, new SqlParameter("@prodid", 24));
    /// </remarks>
    /// <param name="connection">A valid SqlConnection</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command</param>
    /// <param name="dataSet">A dataset wich will contain the resultset generated by the command</param>
    /// <param name="tableNames">This array will be used to create table mappings allowing the DataTables to be referenced
    /// by a user defined name (probably the actual table name)
    /// </param>
    /// <param name="commandParameters">An array of SqlParamters used to execute the command</param>
    public static void FillDataset(SqlConnection connection, CommandType commandType,
      string commandText, DataSet dataSet, string[] tableNames,
      params SqlParameter[] commandParameters)
    {
      FillDataset(connection, null, commandType, commandText, dataSet, tableNames, commandParameters);
    }

    /// <summary>
    /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the specified SqlConnection 
    /// using the provided parameter values. This method will query the database to discover the parameters for the 
    /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
    /// </summary>
    /// <remarks>
    /// This method provides no access to output parameters or the stored procedure's return value parameter.
    /// 
    /// e.g.: 
    /// FillDataset(conn, "GetOrders", ds, new string[] {"orders"}, 24, 36);
    /// </remarks>
    /// <param name="connection">A valid SqlConnection</param>
    /// <param name="spName">The name of the stored procedure</param>
    /// <param name="dataSet">A dataset wich will contain the resultset generated by the command</param>
    /// <param name="tableNames">This array will be used to create table mappings allowing the DataTables to be referenced
    /// by a user defined name (probably the actual table name)
    /// </param>
    /// <param name="parameterValues">An array of objects to be assigned as the input values of the stored procedure</param>
    public static void FillDataset(SqlConnection connection, string spName,
      DataSet dataSet, string[] tableNames,
      params object[] parameterValues)
    {
      if (connection == null) throw new ArgumentNullException("connection");
      if (dataSet == null) throw new ArgumentNullException("dataSet");
      if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

      // If we receive parameter values, we need to figure out where they go
      if ((parameterValues != null) && (parameterValues.Length > 0))
      {
        // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
        SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

        // Assign the provided values to these parameters based on parameter order
        AssignParameterValues(commandParameters, parameterValues);

        // Call the overload that takes an array of SqlParameters
        FillDataset(connection, CommandType.StoredProcedure, spName, dataSet, tableNames, commandParameters);
      }
      else
      {
        // Otherwise we can just call the SP without params
        FillDataset(connection, CommandType.StoredProcedure, spName, dataSet, tableNames);
      }
    }

    /// <summary>
    /// Execute a SqlCommand (that returns a resultset and takes no parameters) against the provided SqlTransaction. 
    /// </summary>
    /// <remarks>
    /// e.g.: 
    /// FillDataset(trans, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"});
    /// </remarks>
    /// <param name="transaction">A valid SqlTransaction</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command</param>
    /// <param name="dataSet">A dataset wich will contain the resultset generated by the command</param>
    /// <param name="tableNames">This array will be used to create table mappings allowing the DataTables to be referenced
    /// by a user defined name (probably the actual table name)
    /// </param>
    public static void FillDataset(SqlTransaction transaction, CommandType commandType,
      string commandText,
      DataSet dataSet, string[] tableNames)
    {
      FillDataset(transaction, commandType, commandText, dataSet, tableNames, null);
    }

    /// <summary>
    /// Execute a SqlCommand (that returns a resultset) against the specified SqlTransaction
    /// using the provided parameters.
    /// </summary>
    /// <remarks>
    /// e.g.: 
    /// FillDataset(trans, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, new SqlParameter("@prodid", 24));
    /// </remarks>
    /// <param name="transaction">A valid SqlTransaction</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command</param>
    /// <param name="dataSet">A dataset wich will contain the resultset generated by the command</param>
    /// <param name="tableNames">This array will be used to create table mappings allowing the DataTables to be referenced
    /// by a user defined name (probably the actual table name)
    /// </param>
    /// <param name="commandParameters">An array of SqlParamters used to execute the command</param>
    public static void FillDataset(SqlTransaction transaction, CommandType commandType,
      string commandText, DataSet dataSet, string[] tableNames,
      params SqlParameter[] commandParameters)
    {
      FillDataset(transaction.Connection, transaction, commandType, commandText, dataSet, tableNames, commandParameters);
    }

    /// <summary>
    /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the specified 
    /// SqlTransaction using the provided parameter values. This method will query the database to discover the parameters for the 
    /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
    /// </summary>
    /// <remarks>
    /// This method provides no access to output parameters or the stored procedure's return value parameter.
    /// 
    /// e.g.: 
    /// FillDataset(trans, "GetOrders", ds, new string[]{"orders"}, 24, 36);
    /// </remarks>
    /// <param name="transaction">A valid SqlTransaction</param>
    /// <param name="spName">The name of the stored procedure</param>
    /// <param name="dataSet">A dataset wich will contain the resultset generated by the command</param>
    /// <param name="tableNames">This array will be used to create table mappings allowing the DataTables to be referenced
    /// by a user defined name (probably the actual table name)
    /// </param>
    /// <param name="parameterValues">An array of objects to be assigned as the input values of the stored procedure</param>
    public static void FillDataset(SqlTransaction transaction, string spName,
      DataSet dataSet, string[] tableNames,
      params object[] parameterValues)
    {
      if (transaction == null) throw new ArgumentNullException("transaction");
      if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
      if (dataSet == null) throw new ArgumentNullException("dataSet");
      if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

      // If we receive parameter values, we need to figure out where they go
      if ((parameterValues != null) && (parameterValues.Length > 0))
      {
        // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
        SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

        // Assign the provided values to these parameters based on parameter order
        AssignParameterValues(commandParameters, parameterValues);

        // Call the overload that takes an array of SqlParameters
        FillDataset(transaction, CommandType.StoredProcedure, spName, dataSet, tableNames, commandParameters);
      }
      else
      {
        // Otherwise we can just call the SP without params
        FillDataset(transaction, CommandType.StoredProcedure, spName, dataSet, tableNames);
      }
    }

    /// <summary>
    /// Private helper method that execute a SqlCommand (that returns a resultset) against the specified SqlTransaction and SqlConnection
    /// using the provided parameters.
    /// </summary>
    /// <remarks>
    /// e.g.: 
    /// FillDataset(conn, trans, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, new SqlParameter("@prodid", 24));
    /// </remarks>
    /// <param name="connection">A valid SqlConnection</param>
    /// <param name="transaction">A valid SqlTransaction</param>
    /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
    /// <param name="commandText">The stored procedure name or T-SQL command</param>
    /// <param name="dataSet">A dataset wich will contain the resultset generated by the command</param>
    /// <param name="tableNames">This array will be used to create table mappings allowing the DataTables to be referenced
    /// by a user defined name (probably the actual table name)
    /// </param>
    /// <param name="commandParameters">An array of SqlParamters used to execute the command</param>
    private static void FillDataset(SqlConnection connection, SqlTransaction transaction, CommandType commandType,
      string commandText, DataSet dataSet, string[] tableNames,
      params SqlParameter[] commandParameters)
    {
      if (connection == null) throw new ArgumentNullException("connection");
      if (dataSet == null) throw new ArgumentNullException("dataSet");

      // Create a command and prepare it for execution
      SqlCommand command = new SqlCommand();
      bool mustCloseConnection = false;
      PrepareCommand(command, connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);

      // Create the DataAdapter & DataSet
      using (SqlDataAdapter dataAdapter = new SqlDataAdapter(command))
      {

        // Add the table mappings specified by the user
        if (tableNames != null && tableNames.Length > 0)
        {
          string tableName = "Table";
          for (int index = 0; index < tableNames.Length; index++)
          {
            if (tableNames[index] == null || tableNames[index].Length == 0) throw new ArgumentException("The tableNames parameter must contain a list of tables, a value was provided as null or empty string.", "tableNames");
            dataAdapter.TableMappings.Add(tableName, tableNames[index]);
            tableName += (index + 1).ToString();
          }
        }

        // Fill the DataSet using default values for DataTable names, etc
        dataAdapter.Fill(dataSet);

        // Detach the SqlParameters from the command object, so they can be used again
        command.Parameters.Clear();
      }

      if (mustCloseConnection)
        connection.Close();
    }
    #endregion

    #region UpdateDataset
    /// <summary>
    /// Executes the respective command for each inserted, updated, or deleted row in the DataSet.
    /// </summary>
    /// <remarks>
    /// e.g.: 
    /// UpdateDataset(conn, insertCommand, deleteCommand, updateCommand, dataSet, "Order");
    /// </remarks>
    /// <param name="insertCommand">A valid transact-SQL statement or stored procedure to insert new records into the data source</param>
    /// <param name="deleteCommand">A valid transact-SQL statement or stored procedure to delete records from the data source</param>
    /// <param name="updateCommand">A valid transact-SQL statement or stored procedure used to update records in the data source</param>
    /// <param name="dataSet">The DataSet used to update the data source</param>
    /// <param name="tableName">The DataTable used to update the data source.</param>
    public static void UpdateDataset(SqlCommand insertCommand, SqlCommand deleteCommand, SqlCommand updateCommand, DataSet dataSet, string tableName)
    {
      if (insertCommand == null) throw new ArgumentNullException("insertCommand");
      if (deleteCommand == null) throw new ArgumentNullException("deleteCommand");
      if (updateCommand == null) throw new ArgumentNullException("updateCommand");
      if (tableName == null || tableName.Length == 0) throw new ArgumentNullException("tableName");

      // Create a SqlDataAdapter, and dispose of it after we are done
      using (SqlDataAdapter dataAdapter = new SqlDataAdapter())
      {
        // Set the data adapter commands
        dataAdapter.UpdateCommand = updateCommand;
        dataAdapter.InsertCommand = insertCommand;
        dataAdapter.DeleteCommand = deleteCommand;

        // Update the dataset changes in the data source
        dataAdapter.Update(dataSet, tableName);

        // Commit all the changes made to the DataSet
        dataSet.AcceptChanges();
      }
    }
    #endregion

    #region CreateCommand
    /// <summary>
    /// Simplify the creation of a Sql command object by allowing
    /// a stored procedure and optional parameters to be provided
    /// </summary>
    /// <remarks>
    /// e.g.: 
    /// SqlCommand command = CreateCommand(conn, "AddCustomer", "CustomerID", "CustomerName");
    /// </remarks>
    /// <param name="connection">A valid SqlConnection object</param>
    /// <param name="spName">The name of the stored procedure</param>
    /// <param name="sourceColumns">An array of string to be assigned as the source columns of the stored procedure parameters</param>
    /// <returns>A valid SqlCommand object</returns>
    public static SqlCommand CreateCommand(SqlConnection connection, string spName, params string[] sourceColumns)
    {
      if (connection == null) throw new ArgumentNullException("connection");
      if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

      // Create a SqlCommand
      SqlCommand cmd = new SqlCommand(spName, connection);
      cmd.CommandType = CommandType.StoredProcedure;

      // If we receive parameter values, we need to figure out where they go
      if ((sourceColumns != null) && (sourceColumns.Length > 0))
      {
        // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
        SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

        // Assign the provided source columns to these parameters based on parameter order
        for (int index = 0; index < sourceColumns.Length; index++)
          commandParameters[index].SourceColumn = sourceColumns[index];

        // Attach the discovered parameters to the SqlCommand object
        AttachParameters(cmd, commandParameters);
      }

      return cmd;
    }
    #endregion

    #region ExecuteNonQueryTypedParams
    /// <summary>
    /// Execute a stored procedure via a SqlCommand (that returns no resultset) against the database specified in 
    /// the connection string using the dataRow column values as the stored procedure's parameters values.
    /// This method will query the database to discover the parameters for the 
    /// stored procedure (the first time each stored procedure is called), and assign the values based on row values.
    /// </summary>
    /// <param name="connectionString">A valid connection string for a SqlConnection</param>
    /// <param name="spName">The name of the stored procedure</param>
    /// <param name="dataRow">The dataRow used to hold the stored procedure's parameter values.</param>
    /// <returns>An int representing the number of rows affected by the command</returns>
    public static int ExecuteNonQueryTypedParams(String connectionString, String spName, DataRow dataRow)
    {
      if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
      if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

      // If the row has values, the store procedure parameters must be initialized
      if (dataRow != null && dataRow.ItemArray.Length > 0)
      {
        // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
        SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

        // Set the parameters values
        AssignParameterValues(commandParameters, dataRow);

        return SqlHelper.ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName, commandParameters);
      }
      else
      {
        return SqlHelper.ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName);
      }
    }

    /// <summary>
    /// Execute a stored procedure via a SqlCommand (that returns no resultset) against the specified SqlConnection 
    /// using the dataRow column values as the stored procedure's parameters values. 
    /// This method will query the database to discover the parameters for the 
    /// stored procedure (the first time each stored procedure is called), and assign the values based on row values.
    /// </summary>
    /// <param name="connection">A valid SqlConnection object</param>
    /// <param name="spName">The name of the stored procedure</param>
    /// <param name="dataRow">The dataRow used to hold the stored procedure's parameter values.</param>
    /// <returns>An int representing the number of rows affected by the command</returns>
    public static int ExecuteNonQueryTypedParams(SqlConnection connection, String spName, DataRow dataRow)
    {
      if (connection == null) throw new ArgumentNullException("connection");
      if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

      // If the row has values, the store procedure parameters must be initialized
      if (dataRow != null && dataRow.ItemArray.Length > 0)
      {
        // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
        SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

        // Set the parameters values
        AssignParameterValues(commandParameters, dataRow);

        return SqlHelper.ExecuteNonQuery(connection, CommandType.StoredProcedure, spName, commandParameters);
      }
      else
      {
        return SqlHelper.ExecuteNonQuery(connection, CommandType.StoredProcedure, spName);
      }
    }

    /// <summary>
    /// Execute a stored procedure via a SqlCommand (that returns no resultset) against the specified
    /// SqlTransaction using the dataRow column values as the stored procedure's parameters values.
    /// This method will query the database to discover the parameters for the 
    /// stored procedure (the first time each stored procedure is called), and assign the values based on row values.
    /// </summary>
    /// <param name="transaction">A valid SqlTransaction object</param>
    /// <param name="spName">The name of the stored procedure</param>
    /// <param name="dataRow">The dataRow used to hold the stored procedure's parameter values.</param>
    /// <returns>An int representing the number of rows affected by the command</returns>
    public static int ExecuteNonQueryTypedParams(SqlTransaction transaction, String spName, DataRow dataRow)
    {
      if (transaction == null) throw new ArgumentNullException("transaction");
      if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
      if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

      // Sf the row has values, the store procedure parameters must be initialized
      if (dataRow != null && dataRow.ItemArray.Length > 0)
      {
        // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
        SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

        // Set the parameters values
        AssignParameterValues(commandParameters, dataRow);

        return SqlHelper.ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName, commandParameters);
      }
      else
      {
        return SqlHelper.ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName);
      }
    }
    #endregion

    #region ExecuteDatasetTypedParams
    /// <summary>
    /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the database specified in 
    /// the connection string using the dataRow column values as the stored procedure's parameters values.
    /// This method will query the database to discover the parameters for the 
    /// stored procedure (the first time each stored procedure is called), and assign the values based on row values.
    /// </summary>
    /// <param name="connectionString">A valid connection string for a SqlConnection</param>
    /// <param name="spName">The name of the stored procedure</param>
    /// <param name="dataRow">The dataRow used to hold the stored procedure's parameter values.</param>
    /// <returns>A dataset containing the resultset generated by the command</returns>
    public static DataSet ExecuteDatasetTypedParams(string connectionString, String spName, DataRow dataRow)
    {
      if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
      if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

      //If the row has values, the store procedure parameters must be initialized
      if (dataRow != null && dataRow.ItemArray.Length > 0)
      {
        // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
        SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

        // Set the parameters values
        AssignParameterValues(commandParameters, dataRow);

        return SqlHelper.ExecuteDataset(connectionString, CommandType.StoredProcedure, spName, commandParameters);
      }
      else
      {
        return SqlHelper.ExecuteDataset(connectionString, CommandType.StoredProcedure, spName);
      }
    }

    /// <summary>
    /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the specified SqlConnection 
    /// using the dataRow column values as the store procedure's parameters values.
    /// This method will query the database to discover the parameters for the 
    /// stored procedure (the first time each stored procedure is called), and assign the values based on row values.
    /// </summary>
    /// <param name="connection">A valid SqlConnection object</param>
    /// <param name="spName">The name of the stored procedure</param>
    /// <param name="dataRow">The dataRow used to hold the stored procedure's parameter values.</param>
    /// <returns>A dataset containing the resultset generated by the command</returns>
    public static DataSet ExecuteDatasetTypedParams(SqlConnection connection, String spName, DataRow dataRow)
    {
      if (connection == null) throw new ArgumentNullException("connection");
      if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

      // If the row has values, the store procedure parameters must be initialized
      if (dataRow != null && dataRow.ItemArray.Length > 0)
      {
        // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
        SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

        // Set the parameters values
        AssignParameterValues(commandParameters, dataRow);

        return SqlHelper.ExecuteDataset(connection, CommandType.StoredProcedure, spName, commandParameters);
      }
      else
      {
        return SqlHelper.ExecuteDataset(connection, CommandType.StoredProcedure, spName);
      }
    }

    /// <summary>
    /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the specified SqlTransaction 
    /// using the dataRow column values as the stored procedure's parameters values.
    /// This method will query the database to discover the parameters for the 
    /// stored procedure (the first time each stored procedure is called), and assign the values based on row values.
    /// </summary>
    /// <param name="transaction">A valid SqlTransaction object</param>
    /// <param name="spName">The name of the stored procedure</param>
    /// <param name="dataRow">The dataRow used to hold the stored procedure's parameter values.</param>
    /// <returns>A dataset containing the resultset generated by the command</returns>
    public static DataSet ExecuteDatasetTypedParams(SqlTransaction transaction, String spName, DataRow dataRow)
    {
      if (transaction == null) throw new ArgumentNullException("transaction");
      if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
      if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

      // If the row has values, the store procedure parameters must be initialized
      if (dataRow != null && dataRow.ItemArray.Length > 0)
      {
        // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
        SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

        // Set the parameters values
        AssignParameterValues(commandParameters, dataRow);

        return SqlHelper.ExecuteDataset(transaction, CommandType.StoredProcedure, spName, commandParameters);
      }
      else
      {
        return SqlHelper.ExecuteDataset(transaction, CommandType.StoredProcedure, spName);
      }
    }

    #endregion

    #region ExecuteReaderTypedParams
    /// <summary>
    /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the database specified in 
    /// the connection string using the dataRow column values as the stored procedure's parameters values.
    /// This method will query the database to discover the parameters for the 
    /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
    /// </summary>
    /// <param name="connectionString">A valid connection string for a SqlConnection</param>
    /// <param name="spName">The name of the stored procedure</param>
    /// <param name="dataRow">The dataRow used to hold the stored procedure's parameter values.</param>
    /// <returns>A SqlDataReader containing the resultset generated by the command</returns>
    public static SqlDataReader ExecuteReaderTypedParams(String connectionString, String spName, DataRow dataRow)
    {
      if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
      if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

      // If the row has values, the store procedure parameters must be initialized
      if (dataRow != null && dataRow.ItemArray.Length > 0)
      {
        // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
        SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

        // Set the parameters values
        AssignParameterValues(commandParameters, dataRow);

        return SqlHelper.ExecuteReader(connectionString, CommandType.StoredProcedure, spName, commandParameters);
      }
      else
      {
        return SqlHelper.ExecuteReader(connectionString, CommandType.StoredProcedure, spName);
      }
    }


    /// <summary>
    /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the specified SqlConnection 
    /// using the dataRow column values as the stored procedure's parameters values.
    /// This method will query the database to discover the parameters for the 
    /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
    /// </summary>
    /// <param name="connection">A valid SqlConnection object</param>
    /// <param name="spName">The name of the stored procedure</param>
    /// <param name="dataRow">The dataRow used to hold the stored procedure's parameter values.</param>
    /// <returns>A SqlDataReader containing the resultset generated by the command</returns>
    public static SqlDataReader ExecuteReaderTypedParams(SqlConnection connection, String spName, DataRow dataRow)
    {
      if (connection == null) throw new ArgumentNullException("connection");
      if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

      // If the row has values, the store procedure parameters must be initialized
      if (dataRow != null && dataRow.ItemArray.Length > 0)
      {
        // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
        SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

        // Set the parameters values
        AssignParameterValues(commandParameters, dataRow);

        return SqlHelper.ExecuteReader(connection, CommandType.StoredProcedure, spName, commandParameters);
      }
      else
      {
        return SqlHelper.ExecuteReader(connection, CommandType.StoredProcedure, spName);
      }
    }

    /// <summary>
    /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the specified SqlTransaction 
    /// using the dataRow column values as the stored procedure's parameters values.
    /// This method will query the database to discover the parameters for the 
    /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
    /// </summary>
    /// <param name="transaction">A valid SqlTransaction object</param>
    /// <param name="spName">The name of the stored procedure</param>
    /// <param name="dataRow">The dataRow used to hold the stored procedure's parameter values.</param>
    /// <returns>A SqlDataReader containing the resultset generated by the command</returns>
    public static SqlDataReader ExecuteReaderTypedParams(SqlTransaction transaction, String spName, DataRow dataRow)
    {
      if (transaction == null) throw new ArgumentNullException("transaction");
      if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
      if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

      // If the row has values, the store procedure parameters must be initialized
      if (dataRow != null && dataRow.ItemArray.Length > 0)
      {
        // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
        SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

        // Set the parameters values
        AssignParameterValues(commandParameters, dataRow);

        return SqlHelper.ExecuteReader(transaction, CommandType.StoredProcedure, spName, commandParameters);
      }
      else
      {
        return SqlHelper.ExecuteReader(transaction, CommandType.StoredProcedure, spName);
      }
    }
    #endregion

    #region ExecuteScalarTypedParams
    /// <summary>
    /// Execute a stored procedure via a SqlCommand (that returns a 1x1 resultset) against the database specified in 
    /// the connection string using the dataRow column values as the stored procedure's parameters values.
    /// This method will query the database to discover the parameters for the 
    /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
    /// </summary>
    /// <param name="connectionString">A valid connection string for a SqlConnection</param>
    /// <param name="spName">The name of the stored procedure</param>
    /// <param name="dataRow">The dataRow used to hold the stored procedure's parameter values.</param>
    /// <returns>An object containing the value in the 1x1 resultset generated by the command</returns>
    public static object ExecuteScalarTypedParams(String connectionString, String spName, DataRow dataRow)
    {
      if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
      if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

      // If the row has values, the store procedure parameters must be initialized
      if (dataRow != null && dataRow.ItemArray.Length > 0)
      {
        // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
        SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

        // Set the parameters values
        AssignParameterValues(commandParameters, dataRow);

        return SqlHelper.ExecuteScalar(connectionString, CommandType.StoredProcedure, spName, commandParameters);
      }
      else
      {
        return SqlHelper.ExecuteScalar(connectionString, CommandType.StoredProcedure, spName);
      }
    }

    /// <summary>
    /// Execute a stored procedure via a SqlCommand (that returns a 1x1 resultset) against the specified SqlConnection 
    /// using the dataRow column values as the stored procedure's parameters values.
    /// This method will query the database to discover the parameters for the 
    /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
    /// </summary>
    /// <param name="connection">A valid SqlConnection object</param>
    /// <param name="spName">The name of the stored procedure</param>
    /// <param name="dataRow">The dataRow used to hold the stored procedure's parameter values.</param>
    /// <returns>An object containing the value in the 1x1 resultset generated by the command</returns>
    public static object ExecuteScalarTypedParams(SqlConnection connection, String spName, DataRow dataRow)
    {
      if (connection == null) throw new ArgumentNullException("connection");
      if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

      // If the row has values, the store procedure parameters must be initialized
      if (dataRow != null && dataRow.ItemArray.Length > 0)
      {
        // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
        SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

        // Set the parameters values
        AssignParameterValues(commandParameters, dataRow);

        return SqlHelper.ExecuteScalar(connection, CommandType.StoredProcedure, spName, commandParameters);
      }
      else
      {
        return SqlHelper.ExecuteScalar(connection, CommandType.StoredProcedure, spName);
      }
    }

    /// <summary>
    /// Execute a stored procedure via a SqlCommand (that returns a 1x1 resultset) against the specified SqlTransaction
    /// using the dataRow column values as the stored procedure's parameters values.
    /// This method will query the database to discover the parameters for the 
    /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
    /// </summary>
    /// <param name="transaction">A valid SqlTransaction object</param>
    /// <param name="spName">The name of the stored procedure</param>
    /// <param name="dataRow">The dataRow used to hold the stored procedure's parameter values.</param>
    /// <returns>An object containing the value in the 1x1 resultset generated by the command</returns>
    public static object ExecuteScalarTypedParams(SqlTransaction transaction, String spName, DataRow dataRow)
    {
      if (transaction == null) throw new ArgumentNullException("transaction");
      if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
      if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

      // If the row has values, the store procedure parameters must be initialized
      if (dataRow != null && dataRow.ItemArray.Length > 0)
      {
        // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
        SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

        // Set the parameters values
        AssignParameterValues(commandParameters, dataRow);

        return SqlHelper.ExecuteScalar(transaction, CommandType.StoredProcedure, spName, commandParameters);
      }
      else
      {
        return SqlHelper.ExecuteScalar(transaction, CommandType.StoredProcedure, spName);
      }
    }
    #endregion

    #region ExecuteXmlReaderTypedParams
    /// <summary>
    /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the specified SqlConnection 
    /// using the dataRow column values as the stored procedure's parameters values.
    /// This method will query the database to discover the parameters for the 
    /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
    /// </summary>
    /// <param name="connection">A valid SqlConnection object</param>
    /// <param name="spName">The name of the stored procedure</param>
    /// <param name="dataRow">The dataRow used to hold the stored procedure's parameter values.</param>
    /// <returns>An XmlReader containing the resultset generated by the command</returns>
    public static XmlReader ExecuteXmlReaderTypedParams(SqlConnection connection, String spName, DataRow dataRow)
    {
      if (connection == null) throw new ArgumentNullException("connection");
      if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

      // If the row has values, the store procedure parameters must be initialized
      if (dataRow != null && dataRow.ItemArray.Length > 0)
      {
        // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
        SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

        // Set the parameters values
        AssignParameterValues(commandParameters, dataRow);

        return SqlHelper.ExecuteXmlReader(connection, CommandType.StoredProcedure, spName, commandParameters);
      }
      else
      {
        return SqlHelper.ExecuteXmlReader(connection, CommandType.StoredProcedure, spName);
      }
    }

    /// <summary>
    /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the specified SqlTransaction 
    /// using the dataRow column values as the stored procedure's parameters values.
    /// This method will query the database to discover the parameters for the 
    /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
    /// </summary>
    /// <param name="transaction">A valid SqlTransaction object</param>
    /// <param name="spName">The name of the stored procedure</param>
    /// <param name="dataRow">The dataRow used to hold the stored procedure's parameter values.</param>
    /// <returns>An XmlReader containing the resultset generated by the command</returns>
    public static XmlReader ExecuteXmlReaderTypedParams(SqlTransaction transaction, String spName, DataRow dataRow)
    {
      if (transaction == null) throw new ArgumentNullException("transaction");
      if (transaction != null && transaction.Connection == null) throw new ArgumentException("The transaction was rollbacked or commited, please provide an open transaction.", "transaction");
      if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

      // If the row has values, the store procedure parameters must be initialized
      if (dataRow != null && dataRow.ItemArray.Length > 0)
      {
        // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
        SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

        // Set the parameters values
        AssignParameterValues(commandParameters, dataRow);

        return SqlHelper.ExecuteXmlReader(transaction, CommandType.StoredProcedure, spName, commandParameters);
      }
      else
      {
        return SqlHelper.ExecuteXmlReader(transaction, CommandType.StoredProcedure, spName);
      }
    }
    #endregion

  }

  /// <summary>
  /// SqlHelperParameterCache provides functions to leverage a static cache of procedure parameters, and the
  /// ability to discover parameters for stored procedures at run-time.
  /// </summary>
  public sealed class SqlHelperParameterCache
  {
    #region private methods, variables, and constructors

    //Since this class provides only static methods, make the default constructor private to prevent 
    //instances from being created with "new SqlHelperParameterCache()"
    private SqlHelperParameterCache() { }

    private static Hashtable paramCache = Hashtable.Synchronized(new Hashtable());

    /// <summary>
    /// Resolve at run time the appropriate set of SqlParameters for a stored procedure
    /// </summary>
    /// <param name="connection">A valid SqlConnection object</param>
    /// <param name="spName">The name of the stored procedure</param>
    /// <param name="includeReturnValueParameter">Whether or not to include their return value parameter</param>
    /// <returns>The parameter array discovered.</returns>
    private static SqlParameter[] DiscoverSpParameterSet(SqlConnection connection, string spName, bool includeReturnValueParameter)
    {
      if (connection == null) throw new ArgumentNullException("connection");
      if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

      SqlCommand cmd = new SqlCommand(spName, connection);
      cmd.CommandType = CommandType.StoredProcedure;

      connection.Open();
      SqlCommandBuilder.DeriveParameters(cmd);
      connection.Close();

      if (!includeReturnValueParameter)
      {
        cmd.Parameters.RemoveAt(0);
      }

      SqlParameter[] discoveredParameters = new SqlParameter[cmd.Parameters.Count];

      cmd.Parameters.CopyTo(discoveredParameters, 0);

      // Init the parameters with a DBNull value
      foreach (SqlParameter discoveredParameter in discoveredParameters)
      {
        discoveredParameter.Value = DBNull.Value;
      }
      return discoveredParameters;
    }

    /// <summary>
    /// Deep copy of cached SqlParameter array
    /// </summary>
    /// <param name="originalParameters"></param>
    /// <returns></returns>
    private static SqlParameter[] CloneParameters(SqlParameter[] originalParameters)
    {
      SqlParameter[] clonedParameters = new SqlParameter[originalParameters.Length];

      for (int i = 0, j = originalParameters.Length; i < j; i++)
      {
        clonedParameters[i] = (SqlParameter)((ICloneable)originalParameters[i]).Clone();
      }

      return clonedParameters;
    }

    #endregion private methods, variables, and constructors

    #region caching functions

    /// <summary>
    /// Add parameter array to the cache
    /// </summary>
    /// <param name="connectionString">A valid connection string for a SqlConnection</param>
    /// <param name="commandText">The stored procedure name or T-SQL command</param>
    /// <param name="commandParameters">An array of SqlParamters to be cached</param>
    public static void CacheParameterSet(string connectionString, string commandText, params SqlParameter[] commandParameters)
    {
      if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
      if (commandText == null || commandText.Length == 0) throw new ArgumentNullException("commandText");

      string hashKey = connectionString + ":" + commandText;

      paramCache[hashKey] = commandParameters;
    }

    /// <summary>
    /// Retrieve a parameter array from the cache
    /// </summary>
    /// <param name="connectionString">A valid connection string for a SqlConnection</param>
    /// <param name="commandText">The stored procedure name or T-SQL command</param>
    /// <returns>An array of SqlParamters</returns>
    public static SqlParameter[] GetCachedParameterSet(string connectionString, string commandText)
    {
      if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
      if (commandText == null || commandText.Length == 0) throw new ArgumentNullException("commandText");

      string hashKey = connectionString + ":" + commandText;

      SqlParameter[] cachedParameters = paramCache[hashKey] as SqlParameter[];
      if (cachedParameters == null)
      {
        return null;
      }
      else
      {
        return CloneParameters(cachedParameters);
      }
    }

    #endregion caching functions

    #region Parameter Discovery Functions

    /// <summary>
    /// Retrieves the set of SqlParameters appropriate for the stored procedure
    /// </summary>
    /// <remarks>
    /// This method will query the database for this information, and then store it in a cache for future requests.
    /// </remarks>
    /// <param name="connectionString">A valid connection string for a SqlConnection</param>
    /// <param name="spName">The name of the stored procedure</param>
    /// <returns>An array of SqlParameters</returns>
    public static SqlParameter[] GetSpParameterSet(string connectionString, string spName)
    {
      return GetSpParameterSet(connectionString, spName, false);
    }

    /// <summary>
    /// Retrieves the set of SqlParameters appropriate for the stored procedure
    /// </summary>
    /// <remarks>
    /// This method will query the database for this information, and then store it in a cache for future requests.
    /// </remarks>
    /// <param name="connectionString">A valid connection string for a SqlConnection</param>
    /// <param name="spName">The name of the stored procedure</param>
    /// <param name="includeReturnValueParameter">A bool value indicating whether the return value parameter should be included in the results</param>
    /// <returns>An array of SqlParameters</returns>
    public static SqlParameter[] GetSpParameterSet(string connectionString, string spName, bool includeReturnValueParameter)
    {
      if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
      if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

      using (SqlConnection connection = new SqlConnection(connectionString))
      {
        return GetSpParameterSetInternal(connection, spName, includeReturnValueParameter);
      }
    }

    /// <summary>
    /// Retrieves the set of SqlParameters appropriate for the stored procedure
    /// </summary>
    /// <remarks>
    /// This method will query the database for this information, and then store it in a cache for future requests.
    /// </remarks>
    /// <param name="connection">A valid SqlConnection object</param>
    /// <param name="spName">The name of the stored procedure</param>
    /// <returns>An array of SqlParameters</returns>
    internal static SqlParameter[] GetSpParameterSet(SqlConnection connection, string spName)
    {
      return GetSpParameterSet(connection, spName, false);
    }

    /// <summary>
    /// Retrieves the set of SqlParameters appropriate for the stored procedure
    /// </summary>
    /// <remarks>
    /// This method will query the database for this information, and then store it in a cache for future requests.
    /// </remarks>
    /// <param name="connection">A valid SqlConnection object</param>
    /// <param name="spName">The name of the stored procedure</param>
    /// <param name="includeReturnValueParameter">A bool value indicating whether the return value parameter should be included in the results</param>
    /// <returns>An array of SqlParameters</returns>
    internal static SqlParameter[] GetSpParameterSet(SqlConnection connection, string spName, bool includeReturnValueParameter)
    {
      if (connection == null) throw new ArgumentNullException("connection");
      using (SqlConnection clonedConnection = (SqlConnection)((ICloneable)connection).Clone())
      {
        return GetSpParameterSetInternal(clonedConnection, spName, includeReturnValueParameter);
      }
    }

    /// <summary>
    /// Retrieves the set of SqlParameters appropriate for the stored procedure
    /// </summary>
    /// <param name="connection">A valid SqlConnection object</param>
    /// <param name="spName">The name of the stored procedure</param>
    /// <param name="includeReturnValueParameter">A bool value indicating whether the return value parameter should be included in the results</param>
    /// <returns>An array of SqlParameters</returns>
    private static SqlParameter[] GetSpParameterSetInternal(SqlConnection connection, string spName, bool includeReturnValueParameter)
    {
      if (connection == null) throw new ArgumentNullException("connection");
      if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

      string hashKey = connection.ConnectionString + ":" + spName + (includeReturnValueParameter ":include ReturnValue Parameter" : "");

      SqlParameter[] cachedParameters;

      cachedParameters = paramCache[hashKey] as SqlParameter[];
      if (cachedParameters == null)
      {
        SqlParameter[] spParameters = DiscoverSpParameterSet(connection, spName, includeReturnValueParameter);
        paramCache[hashKey] = spParameters;
        cachedParameters = spParameters;
      }

      return CloneParameters(cachedParameters);
    }

    #endregion Parameter Discovery Functions

  }

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SqlHelper,数据库访问

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