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C# SQL Helper

Classe para ajudar na realização de operações com a base de dados SQL Server!

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


namespace HSS.Classes
{
    /// <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 System.Data.DataException( 
                        string.Format(CultureInfo.CurrentCulture ,
                            "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(String.Format(CultureInfo.CurrentCulture,"Parameter count does not match Parameter Value count.",null));
            }

            // 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();
                ds.Locale=CultureInfo.CurrentCulture;

                // 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();
                ds.Locale=CultureInfo.CurrentCulture;

                // 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 can´t set its values. 
                // When this happen, the parameters can´t 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);
        }