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// ===============================================================================

// Microsoft Data Access Application Block for .NET
// http://msdn.microsoft.com/library/en-us/dnbda/html/daab-rm.asp
//
// SQLHelper.cs
//
// This file contains the implementations of the SqlHelper and SqlHelperParameterCache
// classes.
//
// For more information see the Data Access Application Block Implementation Overview.
// ===============================================================================
// Release history
// VERSION DESCRIPTION
// 2.0 Added support for FillDataset, UpdateDataset and "Param" helper methods
//
// ===============================================================================
// Copyright (C) 2000-2001 Microsoft Corporation
// All rights reserved.
// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY
// OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT
// LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR
// FITNESS FOR A PARTICULAR PURPOSE.
// ==============================================================================

using System;
using System.Data;
using System.Xml;
using System.Data.SqlClient;
using System.Collections;

namespace SharpContent.ApplicationBlocks.Data
{
/// <summary>
/// The SqlHelper class is intended to encapsulate high performance, scalable best practices for
/// common uses of SqlClient
/// </summary>
public sealed class SqlHelper
{
#region private utility methods & constructors

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

/// <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

/// <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

/// <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
}

/// <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 cant set its values.
// When this happen, the parameters cant 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

/// <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

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