微软的SQLHelper类(含完整中文注释)

using System;

using System.Data;

using System.Xml;

using System.Data.SqlClient;

using System.Collections;

namespace Book.DAL

{

    /// <summary>

    /// SqlServer数据访问帮助类

    /// </summary>

    public sealed class SqlHelper

    {

        #region 私有构造函数和方法

        private SqlHelper() {}

        /// <summary>

        /// 将SqlParameter参数数组(参数值)分配给SqlCommand命令.

        /// 这个方法将给任何一个参数分配DBNull.Value;

        /// 该操作将阻止默认值的使用.

        /// </summary>

        /// <param>命令名</param>

        /// <param>SqlParameters数组</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 )

                    {

                        // 检查未分配值的输出参数,将其分配以DBNull.Value.

                        if ( ( p.Direction == ParameterDirection.InputOutput || p.Direction == ParameterDirection.Input ) && 

                            (p.Value == null))

                        {

                            p.Value = DBNull.Value;

                        }

                        command.Parameters.Add(p);

                    }

                }

            }

        }

        

        /// <summary>

        /// 将DataRow类型的列值分配到SqlParameter参数数组.

        /// </summary>

        /// <param>要分配值的SqlParameter参数数组</param>

        /// <param>将要分配给存储过程参数的DataRow</param>

        private static void AssignParameterValues(SqlParameter[] commandParameters, DataRow dataRow)

        {

            if ((commandParameters == null) || (dataRow == null)) 

            {

                return;

            }

            int i = 0;

            // 设置参数值

            foreach(SqlParameter commandParameter in commandParameters)

            {

                // 创建参数名称,如果不存在,只抛出一个异常.

                if( commandParameter.ParameterName == null || 

                    commandParameter.ParameterName.Length <= 1 )

                    throw new Exception( 

                        string.Format("请提供参数{0}一个有效的名称{1}.", i, commandParameter.ParameterName ) );

                // 从dataRow的表中获取为参数数组中数组名称的列的索引.

                // 如果存在和参数名称相同的列,则将列值赋给当前名称的参数.

                if (dataRow.Table.Columns.IndexOf(commandParameter.ParameterName.Substring(1)) != -1)

                    commandParameter.Value = dataRow[commandParameter.ParameterName.Substring(1)];

                i++;

            }

        }

        

        /// <summary>

        /// 将一个对象数组分配给SqlParameter参数数组.

        /// </summary>

        /// <param>要分配值的SqlParameter参数数组</param>

        /// <param>将要分配给存储过程参数的对象数组</param>

        private static void AssignParameterValues(SqlParameter[] commandParameters, object[] parameterValues)

        {

            if ((commandParameters == null) || (parameterValues == null)) 

            {

                return;

            }

            // 确保对象数组个数与参数个数匹配,如果不匹配,抛出一个异常.

            if (commandParameters.Length != parameterValues.Length)

            {

                throw new ArgumentException("参数值个数与参数不匹配.");

            }

            // 给参数赋值

            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>

        /// 预处理用户提供的命令,数据库连接/事务/命令类型/参数

        /// </summary>

        /// <param>要处理的SqlCommand</param>

        /// <param>数据库连接</param>

        /// <param>一个有效的事务或者是null值</param>

        /// <param>命令类型 (存储过程,命令文本, 其它.)</param>

        /// <param>存储过程名或都T-SQL命令文本</param>

        /// <param>和命令相关联的SqlParameter参数数组,如果没有参数为'null'</param>

        /// <param><c>true</c> 如果连接是打开的,则为true,其它情况下为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;

            }

            // 给命令分配一个数据库连接.

            command.Connection = connection;

            // 设置命令文本(存储过程名或SQL语句)

            command.CommandText = commandText;

            // 分配事务

            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;

            }

            // 设置命令类型.

            command.CommandType = commandType;

            // 分配命令参数

            if (commandParameters != null)

            {

                AttachParameters(command, commandParameters);

            }

            return;

        }

        #endregion 私有构造函数和方法结束

            

        #region ExecuteNonQuery命令

        /// <summary>

        /// 执行指定连接字符串,类型的SqlCommand.

        /// </summary>

        /// <remarks>

        /// 示例:  

        ///  int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders");

        /// </remarks>

        /// <param>一个有效的数据库连接字符串</param>

        /// <param>命令类型 (存储过程,命令文本, 其它.)</param>

        /// <param>存储过程名称或SQL语句</param>

        /// <returns>返回命令影响的行数</returns>

        public static int ExecuteNonQuery(string connectionString, CommandType commandType, string commandText)

        {

            return ExecuteNonQuery(connectionString, commandType, commandText, (SqlParameter[])null);

        }

        

        /// <summary>

        /// 执行指定连接字符串,类型的SqlCommand.如果没有提供参数,不返回结果.

        /// </summary>

        /// <remarks>

        /// 示例:  

        ///  int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));

        /// </remarks>

        /// <param>一个有效的数据库连接字符串</param>

        /// <param>命令类型 (存储过程,命令文本, 其它.)</param>

        /// <param>存储过程名称或SQL语句</param>

        /// <param>SqlParameter参数数组</param>

        /// <returns>返回命令影响的行数</returns>

        public static int ExecuteNonQuery(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)

        {

            if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );

            using (SqlConnection connection = new SqlConnection(connectionString))

            {

                connection.Open();

                return ExecuteNonQuery(connection, commandType, commandText, commandParameters);

            }

        }

        

        /// <summary>

        /// 执行指定连接字符串的存储过程,将对象数组的值赋给存储过程参数,

        /// 此方法需要在参数缓存方法中探索参数并生成参数.

        /// </summary>

        /// <remarks>

        /// 这个方法没有提供访问输出参数和返回值.

        /// 示例:  

        ///  int result = ExecuteNonQuery(connString, "PublishOrders", 24, 36);

        /// </remarks>

        /// <param>一个有效的数据库连接字符串/param>

        /// <param>存储过程名称</param>

        /// <param>分配到存储过程输入参数的对象数组</param>

        /// <returns>返回受影响的行数</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" );

            // 如果存在参数值

            if ((parameterValues != null) && (parameterValues.Length > 0)) 

            {

                // 从探索存储过程参数(加载到缓存)并分配给存储过程参数数组.

                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                // 给存储过程参数赋值

                AssignParameterValues(commandParameters, parameterValues);

                return ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName, commandParameters);

            }

            else 

            {

                // 没有参数情况下

                return ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName);

            }

        }

        

        /// <summary>

        /// 执行指定数据库连接对象的命令 

        /// </summary>

        /// <remarks>

        /// 示例:  

        ///  int result = ExecuteNonQuery(conn, CommandType.StoredProcedure, "PublishOrders");

        /// </remarks>

        /// <param>一个有效的数据库连接对象</param>

        /// <param>命令类型(存储过程,命令文本或其它.)</param>

        /// <param>存储过程名称或T-SQL语句</param>

        /// <returns>返回影响的行数</returns>

        public static int ExecuteNonQuery(SqlConnection connection, CommandType commandType, string commandText)

        {

            return ExecuteNonQuery(connection, commandType, commandText, (SqlParameter[])null);

        }

        

        /// <summary>

        /// 执行指定数据库连接对象的命令

        /// </summary>

        /// <remarks>

        /// 示例:  

        ///  int result = ExecuteNonQuery(conn, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));

        /// </remarks>

        /// <param>一个有效的数据库连接对象</param>

        /// <param>命令类型(存储过程,命令文本或其它.)</param>

        /// <param>T存储过程名称或T-SQL语句</param>

        /// <param>SqlParamter参数数组</param>

        /// <returns>返回影响的行数</returns>

        public static int ExecuteNonQuery(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)

        {    

            if( connection == null ) throw new ArgumentNullException( "connection" );

            // 创建SqlCommand命令,并进行预处理

            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();

            

            // 清除参数,以便再次使用.

            cmd.Parameters.Clear();

            if( mustCloseConnection )

                connection.Close();

            return retval;

        }

        

        /// <summary>

        /// 执行指定数据库连接对象的命令,将对象数组的值赋给存储过程参数.

        /// </summary>

        /// <remarks>

        /// 此方法不提供访问存储过程输出参数和返回值

        /// 示例:  

        ///  int result = ExecuteNonQuery(conn, "PublishOrders", 24, 36);

        /// </remarks>

        /// <param>一个有效的数据库连接对象</param>

        /// <param>存储过程名</param>

        /// <param>分配给存储过程输入参数的对象数组</param>

        /// <returns>返回影响的行数</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" );

            // 如果有参数值

            if ((parameterValues != null) && (parameterValues.Length > 0)) 

            {

                // 从缓存中加载存储过程参数

                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                // 给存储过程分配参数值

                AssignParameterValues(commandParameters, parameterValues);

                return ExecuteNonQuery(connection, CommandType.StoredProcedure, spName, commandParameters);

            }

            else 

            {

                return ExecuteNonQuery(connection, CommandType.StoredProcedure, spName);

            }

        }

        

        /// <summary>

        /// 执行带事务的SqlCommand.

        /// </summary>

        /// <remarks>

        /// 示例.:  

        ///  int result = ExecuteNonQuery(trans, CommandType.StoredProcedure, "PublishOrders");

        /// </remarks>

        /// <param>一个有效的数据库连接对象</param>

        /// <param>命令类型(存储过程,命令文本或其它.)</param>

        /// <param>存储过程名称或T-SQL语句</param>

        /// <returns>返回影响的行数/returns>

        public static int ExecuteNonQuery(SqlTransaction transaction, CommandType commandType, string commandText)

        {

            return ExecuteNonQuery(transaction, commandType, commandText, (SqlParameter[])null);

        }

        

        /// <summary>

        /// 执行带事务的SqlCommand(指定参数).

        /// </summary>

        /// <remarks>

        /// 示例:  

        ///  int result = ExecuteNonQuery(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));

        /// </remarks>

        /// <param>一个有效的数据库连接对象</param>

        /// <param>命令类型(存储过程,命令文本或其它.)</param>

        /// <param>存储过程名称或T-SQL语句</param>

        /// <param>SqlParamter参数数组</param>

        /// <returns>返回影响的行数</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" );

            // 预处理

            SqlCommand cmd = new SqlCommand();

            bool mustCloseConnection = false;

            PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection );

                

            // 执行

            int retval = cmd.ExecuteNonQuery();

                

            // 清除参数集,以便再次使用.

            cmd.Parameters.Clear();

            return retval;

        }

        

        /// <summary>

        /// 执行带事务的SqlCommand(指定参数值).

        /// </summary>

        /// <remarks>

        /// 此方法不提供访问存储过程输出参数和返回值

        /// 示例:  

        ///  int result = ExecuteNonQuery(conn, trans, "PublishOrders", 24, 36);

        /// </remarks>

        /// <param>一个有效的数据库连接对象</param>

        /// <param>存储过程名</param>

        /// <param>分配给存储过程输入参数的对象数组</param>

        /// <returns>返回受影响的行数</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" );

            // 如果有参数值

            if ((parameterValues != null) && (parameterValues.Length > 0)) 

            {

                // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()

                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                // 给存储过程参数赋值

                AssignParameterValues(commandParameters, parameterValues);

                // 调用重载方法

                return ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName, commandParameters);

            }

            else 

            {

                // 没有参数值

                return ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName);

            }

        }

        #endregion ExecuteNonQuery方法结束

            

        #region ExecuteDataset方法

        /// <summary>

        /// 执行指定数据库连接字符串的命令,返回DataSet.

        /// </summary>

        /// <remarks>

        /// 示例:  

        ///  DataSet ds = ExecuteDataset(connString, CommandType.StoredProcedure, "GetOrders");

        /// </remarks>

        /// <param>一个有效的数据库连接字符串</param>

        /// <param>命令类型 (存储过程,命令文本或其它)</param>

        /// <param>存储过程名称或T-SQL语句</param>

        /// <returns>返回一个包含结果集的DataSet</returns>

        public static DataSet ExecuteDataset(string connectionString, CommandType commandType, string commandText)

        {

            return ExecuteDataset(connectionString, commandType, commandText, (SqlParameter[])null);

        }

        

        /// <summary>

        /// 执行指定数据库连接字符串的命令,返回DataSet.

        /// </summary>

        /// <remarks>

        /// 示例: 

        ///  DataSet ds = ExecuteDataset(connString, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));

        /// </remarks>

        /// <param>一个有效的数据库连接字符串</param>

        /// <param>命令类型 (存储过程,命令文本或其它)</param>

        /// <param>存储过程名称或T-SQL语句</param>

        /// <param>SqlParamters参数数组</param>

        /// <returns>返回一个包含结果集的DataSet</returns>

        public static DataSet ExecuteDataset(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)

        {

            if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );

            // 创建并打开数据库连接对象,操作完成释放对象.

            using (SqlConnection connection = new SqlConnection(connectionString))

            {

                connection.Open();

                // 调用指定数据库连接字符串重载方法.

                return ExecuteDataset(connection, commandType, commandText, commandParameters);

            }

        }

        

        /// <summary>

        /// 执行指定数据库连接字符串的命令,直接提供参数值,返回DataSet.

        /// </summary>

        /// <remarks>

        /// 此方法不提供访问存储过程输出参数和返回值.

        /// 示例: 

        ///  DataSet ds = ExecuteDataset(connString, "GetOrders", 24, 36);

        /// </remarks>

        /// <param>一个有效的数据库连接字符串</param>

        /// <param>存储过程名</param>

        /// <param>分配给存储过程输入参数的对象数组</param>

        /// <returns>返回一个包含结果集的DataSet</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 ((parameterValues != null) && (parameterValues.Length > 0)) 

            {

                // 从缓存中检索存储过程参数

                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                // 给存储过程参数分配值

                AssignParameterValues(commandParameters, parameterValues);

                return ExecuteDataset(connectionString, CommandType.StoredProcedure, spName, commandParameters);

            }

            else 

            {

                return ExecuteDataset(connectionString, CommandType.StoredProcedure, spName);

            }

        }

        

        /// <summary>

        /// 执行指定数据库连接对象的命令,返回DataSet.

        /// </summary>

        /// <remarks>

        /// 示例:  

        ///  DataSet ds = ExecuteDataset(conn, CommandType.StoredProcedure, "GetOrders");

        /// </remarks>

        /// <param>一个有效的数据库连接对象</param>

        /// <param>命令类型 (存储过程,命令文本或其它)</param>

        /// <param>存储过程名或T-SQL语句</param>

        /// <returns>返回一个包含结果集的DataSet</returns>

        public static DataSet ExecuteDataset(SqlConnection connection, CommandType commandType, string commandText)

        {

            return ExecuteDataset(connection, commandType, commandText, (SqlParameter[])null);

        }

        

        /// <summary>

        /// 执行指定数据库连接对象的命令,指定存储过程参数,返回DataSet.

        /// </summary>

        /// <remarks>

        /// 示例:  

        ///  DataSet ds = ExecuteDataset(conn, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));

        /// </remarks>

        /// <param>一个有效的数据库连接对象</param>

        /// <param>命令类型 (存储过程,命令文本或其它)</param>

        /// <param>存储过程名或T-SQL语句</param>

        /// <param>SqlParamter参数数组</param>

        /// <returns>返回一个包含结果集的DataSet</returns>

        public static DataSet ExecuteDataset(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)

        {

            if( connection == null ) throw new ArgumentNullException( "connection" );

            // 预处理

            SqlCommand cmd = new SqlCommand();

            bool mustCloseConnection = false;

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

                

            // 创建SqlDataAdapter和DataSet.

            using( SqlDataAdapter da = new SqlDataAdapter(cmd) )

            {

                DataSet ds = new DataSet();

                // 填充DataSet.

                da.Fill(ds);

                

                cmd.Parameters.Clear();

                if( mustCloseConnection )

                    connection.Close();

                return ds;

            }    

        }

        

        /// <summary>

        /// 执行指定数据库连接对象的命令,指定参数值,返回DataSet.

        /// </summary>

        /// <remarks>

        /// 此方法不提供访问存储过程输入参数和返回值.

        /// 示例.:  

        ///  DataSet ds = ExecuteDataset(conn, "GetOrders", 24, 36);

        /// </remarks>

        /// <param>一个有效的数据库连接对象</param>

        /// <param>存储过程名</param>

        /// <param>分配给存储过程输入参数的对象数组</param>

        /// <returns>返回一个包含结果集的DataSet</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 ((parameterValues != null) && (parameterValues.Length > 0)) 

            {

                // 比缓存中加载存储过程参数

                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                // 给存储过程参数分配值

                AssignParameterValues(commandParameters, parameterValues);

                return ExecuteDataset(connection, CommandType.StoredProcedure, spName, commandParameters);

            }

            else 

            {

                return ExecuteDataset(connection, CommandType.StoredProcedure, spName);

            }

        }

        

        /// <summary>

        /// 执行指定事务的命令,返回DataSet.

        /// </summary>

        /// <remarks>

        /// 示例:  

        ///  DataSet ds = ExecuteDataset(trans, CommandType.StoredProcedure, "GetOrders");

        /// </remarks>

        /// <param>事务</param>

        /// <param>命令类型 (存储过程,命令文本或其它)</param>

        /// <param>存储过程名或T-SQL语句</param>

        /// <returns>返回一个包含结果集的DataSet</returns>

        public static DataSet ExecuteDataset(SqlTransaction transaction, CommandType commandType, string commandText)

        {

            return ExecuteDataset(transaction, commandType, commandText, (SqlParameter[])null);

        }

        

        /// <summary>

        /// 执行指定事务的命令,指定参数,返回DataSet.

        /// </summary>

        /// <remarks>

        /// 示例:  

        ///  DataSet ds = ExecuteDataset(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));

        /// </remarks>

        /// <param>事务</param>

        /// <param>命令类型 (存储过程,命令文本或其它)</param>

        /// <param>存储过程名或T-SQL语句</param>

        /// <param>SqlParamter参数数组</param>

        /// <returns>返回一个包含结果集的DataSet</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" );

            // 预处理

            SqlCommand cmd = new SqlCommand();

            bool mustCloseConnection = false;

            PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection );

                

            // 创建 DataAdapter & DataSet

            using( SqlDataAdapter da = new SqlDataAdapter(cmd) )

            {

                DataSet ds = new DataSet();

                da.Fill(ds);

                cmd.Parameters.Clear();

                return ds;

            }    

        }

        

        /// <summary>

        /// 执行指定事务的命令,指定参数值,返回DataSet.

        /// </summary>

        /// <remarks>

        /// 此方法不提供访问存储过程输入参数和返回值.

        /// 示例.:  

        ///  DataSet ds = ExecuteDataset(trans, "GetOrders", 24, 36);

        /// </remarks>

        /// <param>事务</param>

        /// <param>存储过程名</param>

        /// <param>分配给存储过程输入参数的对象数组</param>

        /// <returns>返回一个包含结果集的DataSet</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 ((parameterValues != null) && (parameterValues.Length > 0)) 

            {

                // 从缓存中加载存储过程参数

                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                // 给存储过程参数分配值

                AssignParameterValues(commandParameters, parameterValues);

                return ExecuteDataset(transaction, CommandType.StoredProcedure, spName, commandParameters);

            }

            else 

            {

                return ExecuteDataset(transaction, CommandType.StoredProcedure, spName);

            }

        }

        #endregion ExecuteDataset数据集命令结束

        

        #region ExecuteReader 数据阅读器

        /// <summary>

        /// 枚举,标识数据库连接是由SqlHelper提供还是由调用者提供

        /// </summary>

        private enum SqlConnectionOwnership    

        {

            /// <summary>由SqlHelper提供连接</summary>

            Internal, 

            /// <summary>由调用者提供连接</summary>

            External

        }

        

        /// <summary>

        /// 执行指定数据库连接对象的数据阅读器.

        /// </summary>

        /// <remarks>

        /// 如果是SqlHelper打开连接,当连接关闭DataReader也将关闭.

        /// 如果是调用都打开连接,DataReader由调用都管理.

        /// </remarks>

        /// <param>一个有效的数据库连接对象</param>

        /// <param>一个有效的事务,或者为 'null'</param>

        /// <param>命令类型 (存储过程,命令文本或其它)</param>

        /// <param>存储过程名或T-SQL语句</param>

        /// <param>SqlParameters参数数组,如果没有参数则为'null'</param>

        /// <param>标识数据库连接对象是由调用者提供还是由SqlHelper提供</param>

        /// <returns>返回包含结果集的SqlDataReader</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;

            // 创建命令

            SqlCommand cmd = new SqlCommand();

            try

            {

                PrepareCommand(cmd, connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection );

            

                // 创建数据阅读器

                SqlDataReader dataReader;

                if (connectionOwnership == SqlConnectionOwnership.External)

                {

                    dataReader = cmd.ExecuteReader();

                }

                else

                {

                    dataReader = cmd.ExecuteReader(CommandBehavior.CloseConnection);

                }

            

                // 清除参数,以便再次使用..

                // HACK: There is a problem here, the output parameter values are fletched 

                // when the reader is closed, so if the parameters are detached from the command

                // then the SqlReader can磘 set its values. 

                // When this happen, the parameters can磘 be used again in other command.

                bool canClear = true;

                foreach(SqlParameter commandParameter in cmd.Parameters)

                {

                    if (commandParameter.Direction != ParameterDirection.Input)

                        canClear = false;

                }

            

                if (canClear)

                {

                    cmd.Parameters.Clear();

                }

                return dataReader;

            }

            catch

            {

                if( mustCloseConnection )

                    connection.Close();

                throw;

            }

        }

        

        /// <summary>

        /// 执行指定数据库连接字符串的数据阅读器.

        /// </summary>

        /// <remarks>

        /// 示例:  

        ///  SqlDataReader dr = ExecuteReader(connString, CommandType.StoredProcedure, "GetOrders");

        /// </remarks>

        /// <param>一个有效的数据库连接字符串</param>

        /// <param>命令类型 (存储过程,命令文本或其它)</param>

        /// <param>存储过程名或T-SQL语句</param>

        /// <returns>返回包含结果集的SqlDataReader</returns>

        public static SqlDataReader ExecuteReader(string connectionString, CommandType commandType, string commandText)

        {

            return ExecuteReader(connectionString, commandType, commandText, (SqlParameter[])null);

        }

        

        /// <summary>

        /// 执行指定数据库连接字符串的数据阅读器,指定参数.

        /// </summary>

        /// <remarks>

        /// 示例:  

        ///  SqlDataReader dr = ExecuteReader(connString, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));

        /// </remarks>

        /// <param>一个有效的数据库连接字符串</param>

        /// <param>命令类型 (存储过程,命令文本或其它)</param>

        /// <param>存储过程名或T-SQL语句</param>

        /// <param>SqlParamter参数数组(new SqlParameter("@prodid", 24))</param>

        /// <returns>返回包含结果集的SqlDataReader</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();

                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>

        /// 执行指定数据库连接字符串的数据阅读器,指定参数值.

        /// </summary>

        /// <remarks>

        /// 此方法不提供访问存储过程输出参数和返回值参数.

        /// 示例:  

        ///  SqlDataReader dr = ExecuteReader(connString, "GetOrders", 24, 36);

        /// </remarks>

        /// <param>一个有效的数据库连接字符串</param>

        /// <param>存储过程名</param>

        /// <param>分配给存储过程输入参数的对象数组</param>

        /// <returns>返回包含结果集的SqlDataReader</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 ((parameterValues != null) && (parameterValues.Length > 0)) 

            {

                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                AssignParameterValues(commandParameters, parameterValues);

                return ExecuteReader(connectionString, CommandType.StoredProcedure, spName, commandParameters);

            }

            else 

            {

                return ExecuteReader(connectionString, CommandType.StoredProcedure, spName);

            }

        }

        

        /// <summary>

        /// 执行指定数据库连接对象的数据阅读器.

        /// </summary>

        /// <remarks>

        /// 示例:  

        ///  SqlDataReader dr = ExecuteReader(conn, CommandType.StoredProcedure, "GetOrders");

        /// </remarks>

        /// <param>一个有效的数据库连接对象</param>

        /// <param>命令类型 (存储过程,命令文本或其它)</param>

        /// <param>存储过程名或T-SQL语句</param>

        /// <returns>返回包含结果集的SqlDataReader</returns>

        public static SqlDataReader ExecuteReader(SqlConnection connection, CommandType commandType, string commandText)

        {

            return ExecuteReader(connection, commandType, commandText, (SqlParameter[])null);

        }

        

        /// <summary>

        /// [调用者方式]执行指定数据库连接对象的数据阅读器,指定参数.

        /// </summary>

        /// <remarks>

        /// 示例:  

        ///  SqlDataReader dr = ExecuteReader(conn, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));

        /// </remarks>

        /// <param>一个有效的数据库连接对象</param>

        /// <param>命令类型 (存储过程,命令文本或其它)</param>

        /// <param>命令类型 (存储过程,命令文本或其它)</param>

        /// <param>SqlParamter参数数组</param>

        /// <returns>返回包含结果集的SqlDataReader</returns>

        public static SqlDataReader ExecuteReader(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)

        {

            return ExecuteReader(connection, (SqlTransaction)null, commandType, commandText, commandParameters, SqlConnectionOwnership.External);

        }

        

        /// <summary>

        /// [调用者方式]执行指定数据库连接对象的数据阅读器,指定参数值.

        /// </summary>

        /// <remarks>

        /// 此方法不提供访问存储过程输出参数和返回值参数.

        /// 示例:  

        ///  SqlDataReader dr = ExecuteReader(conn, "GetOrders", 24, 36);

        /// </remarks>

        /// <param>一个有效的数据库连接对象</param>

        /// <param>T存储过程名</param>

        /// <param>分配给存储过程输入参数的对象数组</param>

        /// <returns>返回包含结果集的SqlDataReader</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 ((parameterValues != null) && (parameterValues.Length > 0)) 

            {

                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                AssignParameterValues(commandParameters, parameterValues);

                return ExecuteReader(connection, CommandType.StoredProcedure, spName, commandParameters);

            }

            else 

            {

                return ExecuteReader(connection, CommandType.StoredProcedure, spName);

            }

        }

        

        /// <summary>

        /// [调用者方式]执行指定数据库事务的数据阅读器,指定参数值.

        /// </summary>

        /// <remarks>

        /// 示例:  

        ///  SqlDataReader dr = ExecuteReader(trans, CommandType.StoredProcedure, "GetOrders");

        /// </remarks>

        /// <param>一个有效的连接事务</param>

        /// <param>命令类型 (存储过程,命令文本或其它)</param>

        /// <param>存储过程名称或T-SQL语句</param>

        /// <returns>返回包含结果集的SqlDataReader</returns>

        public static SqlDataReader ExecuteReader(SqlTransaction transaction, CommandType commandType, string commandText)

        {

            return ExecuteReader(transaction, commandType, commandText, (SqlParameter[])null);

        }

        

        /// <summary>

        /// [调用者方式]执行指定数据库事务的数据阅读器,指定参数.

        /// </summary>

        /// <remarks>

        /// 示例:  

        ///   SqlDataReader dr = ExecuteReader(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));

        /// </remarks>

        /// <param>一个有效的连接事务</param>

        /// <param>命令类型 (存储过程,命令文本或其它)</param>

        /// <param>存储过程名称或T-SQL语句</param>

        /// <param>分配给命令的SqlParamter参数数组</param>

        /// <returns>返回包含结果集的SqlDataReader</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" );

            return ExecuteReader(transaction.Connection, transaction, commandType, commandText, commandParameters, SqlConnectionOwnership.External);

        }

        

        /// <summary>

        /// [调用者方式]执行指定数据库事务的数据阅读器,指定参数值.

        /// </summary>

        /// <remarks>

        /// 此方法不提供访问存储过程输出参数和返回值参数.

        /// 

        /// 示例:  

        ///  SqlDataReader dr = ExecuteReader(trans, "GetOrders", 24, 36);

        /// </remarks>

        /// <param>一个有效的连接事务</param>

        /// <param>存储过程名称</param>

        /// <param>分配给存储过程输入参数的对象数组</param>

        /// <returns>返回包含结果集的SqlDataReader</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" );

            // 如果有参数值

            if ((parameterValues != null) && (parameterValues.Length > 0)) 

            {

                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                AssignParameterValues(commandParameters, parameterValues);

                return ExecuteReader(transaction, CommandType.StoredProcedure, spName, commandParameters);

            }

            else 

            {

                // 没有参数值

                return ExecuteReader(transaction, CommandType.StoredProcedure, spName);

            }

        }

        #endregion ExecuteReader数据阅读器

            

        #region ExecuteScalar 返回结果集中的第一行第一列        

        /// <summary>

        /// 执行指定数据库连接字符串的命令,返回结果集中的第一行第一列.

        /// </summary>

        /// <remarks>

        /// 示例:  

        ///  int orderCount = (int)ExecuteScalar(connString, CommandType.StoredProcedure, "GetOrderCount");

        /// </remarks>

        /// <param>一个有效的数据库连接字符串</param>

        /// <param>命令类型 (存储过程,命令文本或其它)</param>

        /// <param>存储过程名称或T-SQL语句</param>

        /// <returns>返回结果集中的第一行第一列</returns>

        public static object ExecuteScalar(string connectionString, CommandType commandType, string commandText)

        {

            // 执行参数为空的方法

            return ExecuteScalar(connectionString, commandType, commandText, (SqlParameter[])null);

        }

        

        /// <summary>

        /// 执行指定数据库连接字符串的命令,指定参数,返回结果集中的第一行第一列.

        /// </summary>

        /// <remarks>

        /// 示例:  

        ///  int orderCount = (int)ExecuteScalar(connString, CommandType.StoredProcedure, "GetOrderCount", new SqlParameter("@prodid", 24));

        /// </remarks>

        /// <param>一个有效的数据库连接字符串</param>

        /// <param>命令类型 (存储过程,命令文本或其它)</param>

        /// <param>存储过程名称或T-SQL语句</param>

        /// <param>分配给命令的SqlParamter参数数组</param>

        /// <returns>返回结果集中的第一行第一列</returns>

        public static object ExecuteScalar(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)

        {

            if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );

            // 创建并打开数据库连接对象,操作完成释放对象.

            using (SqlConnection connection = new SqlConnection(connectionString))

            {

                connection.Open();

                // 调用指定数据库连接字符串重载方法.

                return ExecuteScalar(connection, commandType, commandText, commandParameters);

            }

        }

        

        /// <summary>

        /// 执行指定数据库连接字符串的命令,指定参数值,返回结果集中的第一行第一列.

        /// </summary>

        /// <remarks>

        /// 此方法不提供访问存储过程输出参数和返回值参数.

        /// 

        /// 示例:  

        ///  int orderCount = (int)ExecuteScalar(connString, "GetOrderCount", 24, 36);

        /// </remarks>

        /// <param>一个有效的数据库连接字符串</param>

        /// <param>存储过程名称</param>

        /// <param>分配给存储过程输入参数的对象数组</param>

        /// <returns>返回结果集中的第一行第一列</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" );

            

            // 如果有参数值

            if ((parameterValues != null) && (parameterValues.Length > 0)) 

            {

                // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()

                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                // 给存储过程参数赋值

                AssignParameterValues(commandParameters, parameterValues);

                // 调用重载方法

                return ExecuteScalar(connectionString, CommandType.StoredProcedure, spName, commandParameters);

            }

            else 

            {

                // 没有参数值

                return ExecuteScalar(connectionString, CommandType.StoredProcedure, spName);

            }

        }

        

        /// <summary>

        /// 执行指定数据库连接对象的命令,返回结果集中的第一行第一列.

        /// </summary>

        /// <remarks>

        /// 示例:  

        ///  int orderCount = (int)ExecuteScalar(conn, CommandType.StoredProcedure, "GetOrderCount");

        /// </remarks>

        /// <param>一个有效的数据库连接对象</param>

        /// <param>命令类型 (存储过程,命令文本或其它)</param>

        /// <param>存储过程名称或T-SQL语句</param>

        /// <returns>返回结果集中的第一行第一列</returns>

        public static object ExecuteScalar(SqlConnection connection, CommandType commandType, string commandText)

        {

            // 执行参数为空的方法

            return ExecuteScalar(connection, commandType, commandText, (SqlParameter[])null);

        }

        

        /// <summary>

        /// 执行指定数据库连接对象的命令,指定参数,返回结果集中的第一行第一列.

        /// </summary>

        /// <remarks>

        /// 示例:  

        ///  int orderCount = (int)ExecuteScalar(conn, CommandType.StoredProcedure, "GetOrderCount", new SqlParameter("@prodid", 24));

        /// </remarks>

        /// <param>一个有效的数据库连接对象</param>

        /// <param>命令类型 (存储过程,命令文本或其它)</param>

        /// <param>存储过程名称或T-SQL语句</param>

        /// <param>分配给命令的SqlParamter参数数组</param>

        /// <returns>返回结果集中的第一行第一列</returns>

        public static object ExecuteScalar(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)

        {

            if( connection == null ) throw new ArgumentNullException( "connection" );

            // 创建SqlCommand命令,并进行预处理

            SqlCommand cmd = new SqlCommand();

            bool mustCloseConnection = false;

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

                

            // 执行SqlCommand命令,并返回结果.

            object retval = cmd.ExecuteScalar();

                

            // 清除参数,以便再次使用.

            cmd.Parameters.Clear();

            if( mustCloseConnection )

                connection.Close();

            return retval;

        }

        

        /// <summary>

        /// 执行指定数据库连接对象的命令,指定参数值,返回结果集中的第一行第一列.

        /// </summary>

        /// <remarks>

        /// 此方法不提供访问存储过程输出参数和返回值参数.

        /// 

        /// 示例:  

        ///  int orderCount = (int)ExecuteScalar(conn, "GetOrderCount", 24, 36);

        /// </remarks>

        /// <param>一个有效的数据库连接对象</param>

        /// <param>存储过程名称</param>

        /// <param>分配给存储过程输入参数的对象数组</param>

        /// <returns>返回结果集中的第一行第一列</returns>

        public static object ExecuteScalar(SqlConnection connection, string spName, params object[] parameterValues)

        {

            if( connection == null ) throw new ArgumentNullException( "connection" );

            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // 如果有参数值

            if ((parameterValues != null) && (parameterValues.Length > 0)) 

            {

                // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()

                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                // 给存储过程参数赋值

                AssignParameterValues(commandParameters, parameterValues);

                // 调用重载方法

                return ExecuteScalar(connection, CommandType.StoredProcedure, spName, commandParameters);

            }

            else 

            {

                // 没有参数值

                return ExecuteScalar(connection, CommandType.StoredProcedure, spName);

            }

        }

        

        /// <summary>

        /// 执行指定数据库事务的命令,返回结果集中的第一行第一列.

        /// </summary>

        /// <remarks>

        /// 示例:  

        ///  int orderCount = (int)ExecuteScalar(trans, CommandType.StoredProcedure, "GetOrderCount");

        /// </remarks>

        /// <param>一个有效的连接事务</param>

        /// <param>命令类型 (存储过程,命令文本或其它)</param>

        /// <param>存储过程名称或T-SQL语句</param>

        /// <returns>返回结果集中的第一行第一列</returns>

        public static object ExecuteScalar(SqlTransaction transaction, CommandType commandType, string commandText)

        {

            // 执行参数为空的方法

            return ExecuteScalar(transaction, commandType, commandText, (SqlParameter[])null);

        }

        

        /// <summary>

        /// 执行指定数据库事务的命令,指定参数,返回结果集中的第一行第一列.

        /// </summary>

        /// <remarks>

        /// 示例:  

        ///  int orderCount = (int)ExecuteScalar(trans, CommandType.StoredProcedure, "GetOrderCount", new SqlParameter("@prodid", 24));

        /// </remarks>

        /// <param>一个有效的连接事务</param>

        /// <param>命令类型 (存储过程,命令文本或其它)</param>

        /// <param>存储过程名称或T-SQL语句</param>

        /// <param>分配给命令的SqlParamter参数数组</param>

        /// <returns>返回结果集中的第一行第一列</returns>

        public static object ExecuteScalar(SqlTransaction transaction, CommandType commandType, string commandText, params SqlParameter[] commandParameters)

        {

            if( transaction == null ) throw new ArgumentNullException( "transaction" );

            if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );

            // 创建SqlCommand命令,并进行预处理

            SqlCommand cmd = new SqlCommand();

            bool mustCloseConnection = false;

            PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection );

                

            // 执行SqlCommand命令,并返回结果.

            object retval = cmd.ExecuteScalar();

                

            // 清除参数,以便再次使用.

            cmd.Parameters.Clear();

            return retval;

        }

        

        /// <summary>

        /// 执行指定数据库事务的命令,指定参数值,返回结果集中的第一行第一列.

        /// </summary>

        /// <remarks>

        /// 此方法不提供访问存储过程输出参数和返回值参数.

        /// 

        /// 示例:  

        ///  int orderCount = (int)ExecuteScalar(trans, "GetOrderCount", 24, 36);

        /// </remarks>

        /// <param>一个有效的连接事务</param>

        /// <param>存储过程名称</param>

        /// <param>分配给存储过程输入参数的对象数组</param>

        /// <returns>返回结果集中的第一行第一列</returns>

        public static object ExecuteScalar(SqlTransaction transaction, string spName, params object[] parameterValues)

        {

            if( transaction == null ) throw new ArgumentNullException( "transaction" );

            if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );

            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // 如果有参数值

            if ((parameterValues != null) && (parameterValues.Length > 0)) 

            {

                // PPull the parameters for this stored procedure from the parameter cache ()

                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                // 给存储过程参数赋值

                AssignParameterValues(commandParameters, parameterValues);

                // 调用重载方法

                return ExecuteScalar(transaction, CommandType.StoredProcedure, spName, commandParameters);

            }

            else 

            {

                // 没有参数值

                return ExecuteScalar(transaction, CommandType.StoredProcedure, spName);

            }

        }

        #endregion ExecuteScalar 

               

        #region ExecuteXmlReader XML阅读器

        /// <summary>

        /// 执行指定数据库连接对象的SqlCommand命令,并产生一个XmlReader对象做为结果集返回.

        /// </summary>

        /// <remarks>

        /// 示例:  

        ///  XmlReader r = ExecuteXmlReader(conn, CommandType.StoredProcedure, "GetOrders");

        /// </remarks>

        /// <param>一个有效的数据库连接对象</param>

        /// <param>命令类型 (存储过程,命令文本或其它)</param>

        /// <param>存储过程名称或T-SQL语句 using "FOR XML AUTO"</param>

        /// <returns>返回XmlReader结果集对象.</returns>

        public static XmlReader ExecuteXmlReader(SqlConnection connection, CommandType commandType, string commandText)

        {

            // 执行参数为空的方法

            return ExecuteXmlReader(connection, commandType, commandText, (SqlParameter[])null);

        }

        

        /// <summary>

        /// 执行指定数据库连接对象的SqlCommand命令,并产生一个XmlReader对象做为结果集返回,指定参数.

        /// </summary>

        /// <remarks>

        /// 示例:  

        ///  XmlReader r = ExecuteXmlReader(conn, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));

        /// </remarks>

        /// <param>一个有效的数据库连接对象</param>

        /// <param>命令类型 (存储过程,命令文本或其它)</param>

        /// <param>存储过程名称或T-SQL语句 using "FOR XML AUTO"</param>

        /// <param>分配给命令的SqlParamter参数数组</param>

        /// <returns>返回XmlReader结果集对象.</returns>

        public static XmlReader ExecuteXmlReader(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)

        {

            if( connection == null ) throw new ArgumentNullException( "connection" );

            bool mustCloseConnection = false;

            // 创建SqlCommand命令,并进行预处理

            SqlCommand cmd = new SqlCommand();

            try

            {

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

            

                // 执行命令

                XmlReader retval = cmd.ExecuteXmlReader();

            

                // 清除参数,以便再次使用.

                cmd.Parameters.Clear();

                return retval;

            }

            catch

            {    

                if( mustCloseConnection )

                    connection.Close();

                throw;

            }

        }

        

        /// <summary>

        /// 执行指定数据库连接对象的SqlCommand命令,并产生一个XmlReader对象做为结果集返回,指定参数值.

        /// </summary>

        /// <remarks>

        /// 此方法不提供访问存储过程输出参数和返回值参数.

        /// 

        /// 示例:  

        ///  XmlReader r = ExecuteXmlReader(conn, "GetOrders", 24, 36);

        /// </remarks>

        /// <param>一个有效的数据库连接对象</param>

        /// <param>存储过程名称 using "FOR XML AUTO"</param>

        /// <param>分配给存储过程输入参数的对象数组</param>

        /// <returns>返回XmlReader结果集对象.</returns>

        public static XmlReader ExecuteXmlReader(SqlConnection connection, string spName, params object[] parameterValues)

        {

            if( connection == null ) throw new ArgumentNullException( "connection" );

            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // 如果有参数值

            if ((parameterValues != null) && (parameterValues.Length > 0)) 

            {

                // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()

                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                // 给存储过程参数赋值

                AssignParameterValues(commandParameters, parameterValues);

                // 调用重载方法

                return ExecuteXmlReader(connection, CommandType.StoredProcedure, spName, commandParameters);

            }

            else 

            {

                // 没有参数值

                return ExecuteXmlReader(connection, CommandType.StoredProcedure, spName);

            }

        }

        

        /// <summary>

        /// 执行指定数据库事务的SqlCommand命令,并产生一个XmlReader对象做为结果集返回.

        /// </summary>

        /// <remarks>

        /// 示例:  

        ///  XmlReader r = ExecuteXmlReader(trans, CommandType.StoredProcedure, "GetOrders");

        /// </remarks>

        /// <param>一个有效的连接事务</param>

        /// <param>命令类型 (存储过程,命令文本或其它)</param>

        /// <param>存储过程名称或T-SQL语句 using "FOR XML AUTO"</param>

        /// <returns>返回XmlReader结果集对象.</returns>

        public static XmlReader ExecuteXmlReader(SqlTransaction transaction, CommandType commandType, string commandText)

        {

            // 执行参数为空的方法

            return ExecuteXmlReader(transaction, commandType, commandText, (SqlParameter[])null);

        }

        

        /// <summary>

        /// 执行指定数据库事务的SqlCommand命令,并产生一个XmlReader对象做为结果集返回,指定参数.

        /// </summary>

        /// <remarks>

        /// 示例:  

        ///  XmlReader r = ExecuteXmlReader(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));

        /// </remarks>

        /// <param>一个有效的连接事务</param>

        /// <param>命令类型 (存储过程,命令文本或其它)</param>

        /// <param>存储过程名称或T-SQL语句 using "FOR XML AUTO"</param>

        /// <param>分配给命令的SqlParamter参数数组</param>

        /// <returns>返回XmlReader结果集对象.</returns>

        public static XmlReader ExecuteXmlReader(SqlTransaction transaction, CommandType commandType, string commandText, params SqlParameter[] commandParameters)

        {

            if( transaction == null ) throw new ArgumentNullException( "transaction" );

            if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );

            // 创建SqlCommand命令,并进行预处理

            SqlCommand cmd = new SqlCommand();

            bool mustCloseConnection = false;

            PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection );

            

            // 执行命令

            XmlReader retval = cmd.ExecuteXmlReader();

            

            // 清除参数,以便再次使用.

            cmd.Parameters.Clear();

            return retval;            

        }

        

        /// <summary>

        /// 执行指定数据库事务的SqlCommand命令,并产生一个XmlReader对象做为结果集返回,指定参数值.

        /// </summary>

        /// <remarks>

        /// 此方法不提供访问存储过程输出参数和返回值参数.

        /// 

        /// 示例:  

        ///  XmlReader r = ExecuteXmlReader(trans, "GetOrders", 24, 36);

        /// </remarks>

        /// <param>一个有效的连接事务</param>

        /// <param>存储过程名称</param>

        /// <param>分配给存储过程输入参数的对象数组</param>

        /// <returns>返回一个包含结果集的DataSet.</returns>

        public static XmlReader ExecuteXmlReader(SqlTransaction transaction, string spName, params object[] parameterValues)

        {

            if( transaction == null ) throw new ArgumentNullException( "transaction" );

            if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );

            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // 如果有参数值

            if ((parameterValues != null) && (parameterValues.Length > 0)) 

            {

                // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()

                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                // 给存储过程参数赋值

                AssignParameterValues(commandParameters, parameterValues);

                // 调用重载方法

                return ExecuteXmlReader(transaction, CommandType.StoredProcedure, spName, commandParameters);

            }

            else 

            {

                // 没有参数值

                return ExecuteXmlReader(transaction, CommandType.StoredProcedure, spName);

            }

        }

        #endregion ExecuteXmlReader 阅读器结束

            

        #region FillDataset 填充数据集

        /// <summary>

        /// 执行指定数据库连接字符串的命令,映射数据表并填充数据集.

        /// </summary>

        /// <remarks>

        /// 示例:  

        ///  FillDataset(connString, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"});

        /// </remarks>

        /// <param>一个有效的数据库连接字符串</param>

        /// <param>命令类型 (存储过程,命令文本或其它)</param>

        /// <param>存储过程名称或T-SQL语句</param>

        /// <param>要填充结果集的DataSet实例</param>

        /// <param>表映射的数据表数组

        /// 用户定义的表名 (可有是实际的表名.)</param>

        public static void FillDataset(string connectionString, CommandType commandType, string commandText, DataSet dataSet, string[] tableNames)

        {

            if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );

            if( dataSet == null ) throw new ArgumentNullException( "dataSet" );

            

            // 创建并打开数据库连接对象,操作完成释放对象.

            using (SqlConnection connection = new SqlConnection(connectionString))

            {

                connection.Open();

                // 调用指定数据库连接字符串重载方法.

                FillDataset(connection, commandType, commandText, dataSet, tableNames);

            }

        }

        

        /// <summary>

        /// 执行指定数据库连接字符串的命令,映射数据表并填充数据集.指定命令参数.

        /// </summary>

        /// <remarks>

        /// 示例:  

        ///  FillDataset(connString, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, new SqlParameter("@prodid", 24));

        /// </remarks>

        /// <param>一个有效的数据库连接字符串</param>

        /// <param>命令类型 (存储过程,命令文本或其它)</param>

        /// <param>存储过程名称或T-SQL语句</param>

        /// <param>分配给命令的SqlParamter参数数组</param>

        /// <param>要填充结果集的DataSet实例</param>

        /// <param>表映射的数据表数组

        /// 用户定义的表名 (可有是实际的表名.)

        /// </param>

        public static void FillDataset(string connectionString, CommandType commandType,

            string commandText, DataSet dataSet, string[] tableNames,

            params SqlParameter[] commandParameters)

        {

            if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );

            if( dataSet == null ) throw new ArgumentNullException( "dataSet" );

            // 创建并打开数据库连接对象,操作完成释放对象.

            using (SqlConnection connection = new SqlConnection(connectionString))

            {

                connection.Open();

                // 调用指定数据库连接字符串重载方法.

                FillDataset(connection, commandType, commandText, dataSet, tableNames, commandParameters);

            }

        }

        

        /// <summary>

        /// 执行指定数据库连接字符串的命令,映射数据表并填充数据集,指定存储过程参数值.

        /// </summary>

        /// <remarks>

        /// 此方法不提供访问存储过程输出参数和返回值参数.

        /// 

        /// 示例:  

        ///  FillDataset(connString, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, 24);

        /// </remarks>

        /// <param>一个有效的数据库连接字符串</param>

        /// <param>存储过程名称</param>

        /// <param>要填充结果集的DataSet实例</param>

        /// <param>表映射的数据表数组

        /// 用户定义的表名 (可有是实际的表名.)

        /// </param>    

        /// <param>分配给存储过程输入参数的对象数组</param>

        public static void FillDataset(string connectionString, string spName,

            DataSet dataSet, string[] tableNames,

            params object[] parameterValues)

        {

            if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );

            if( dataSet == null ) throw new ArgumentNullException( "dataSet" );

            // 创建并打开数据库连接对象,操作完成释放对象.

            using (SqlConnection connection = new SqlConnection(connectionString))

            {

                connection.Open();

                // 调用指定数据库连接字符串重载方法.

                FillDataset (connection, spName, dataSet, tableNames, parameterValues);

            }

        }

        

        /// <summary>

        /// 执行指定数据库连接对象的命令,映射数据表并填充数据集.

        /// </summary>

        /// <remarks>

        /// 示例:  

        ///  FillDataset(conn, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"});

        /// </remarks>

        /// <param>一个有效的数据库连接对象</param>

        /// <param>命令类型 (存储过程,命令文本或其它)</param>

        /// <param>存储过程名称或T-SQL语句</param>

        /// <param>要填充结果集的DataSet实例</param>

        /// <param>表映射的数据表数组

        /// 用户定义的表名 (可有是实际的表名.)

        /// </param>    

        public static void FillDataset(SqlConnection connection, CommandType commandType, 

            string commandText, DataSet dataSet, string[] tableNames)

        {

            FillDataset(connection, commandType, commandText, dataSet, tableNames, null);

        }

        

        /// <summary>

        /// 执行指定数据库连接对象的命令,映射数据表并填充数据集,指定参数.

        /// </summary>

        /// <remarks>

        /// 示例:  

        ///  FillDataset(conn, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, new SqlParameter("@prodid", 24));

        /// </remarks>

        /// <param>一个有效的数据库连接对象</param>

        /// <param>命令类型 (存储过程,命令文本或其它)</param>

        /// <param>存储过程名称或T-SQL语句</param>

        /// <param>要填充结果集的DataSet实例</param>

        /// <param>表映射的数据表数组

        /// 用户定义的表名 (可有是实际的表名.)

        /// </param>

        /// <param>分配给命令的SqlParamter参数数组</param>

        public static void FillDataset(SqlConnection connection, CommandType commandType, 

            string commandText, DataSet dataSet, string[] tableNames,

            params SqlParameter[] commandParameters)

        {

            FillDataset(connection, null, commandType, commandText, dataSet, tableNames, commandParameters);

        }

        

        /// <summary>

        /// 执行指定数据库连接对象的命令,映射数据表并填充数据集,指定存储过程参数值.

        /// </summary>

        /// <remarks>

        /// 此方法不提供访问存储过程输出参数和返回值参数.

        /// 

        /// 示例:  

        ///  FillDataset(conn, "GetOrders", ds, new string[] {"orders"}, 24, 36);

        /// </remarks>

        /// <param>一个有效的数据库连接对象</param>

        /// <param>存储过程名称</param>

        /// <param>要填充结果集的DataSet实例</param>

        /// <param>表映射的数据表数组

        /// 用户定义的表名 (可有是实际的表名.)

        /// </param>

        /// <param>分配给存储过程输入参数的对象数组</param>

        public static void FillDataset(SqlConnection connection, string spName, 

            DataSet dataSet, string[] tableNames,

            params object[] parameterValues)

        {

            if ( connection == null ) throw new ArgumentNullException( "connection" );

            if (dataSet == null ) throw new ArgumentNullException( "dataSet" );

            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // 如果有参数值

            if ((parameterValues != null) && (parameterValues.Length > 0)) 

            {

                // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()

                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                // 给存储过程参数赋值

                AssignParameterValues(commandParameters, parameterValues);

                // 调用重载方法

                FillDataset(connection, CommandType.StoredProcedure, spName, dataSet, tableNames, commandParameters);

            }

            else 

            {

                // 没有参数值

                FillDataset(connection, CommandType.StoredProcedure, spName, dataSet, tableNames);

            }    

        }

        

        /// <summary>

        /// 执行指定数据库事务的命令,映射数据表并填充数据集.

        /// </summary>

        /// <remarks>

        /// 示例:  

        ///  FillDataset(trans, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"});

        /// </remarks>

        /// <param>一个有效的连接事务</param>

        /// <param>命令类型 (存储过程,命令文本或其它)</param>

        /// <param>存储过程名称或T-SQL语句</param>

        /// <param>要填充结果集的DataSet实例</param>

        /// <param>表映射的数据表数组

        /// 用户定义的表名 (可有是实际的表名.)

        /// </param>

        public static void FillDataset(SqlTransaction transaction, CommandType commandType, 

            string commandText,

            DataSet dataSet, string[] tableNames)

        {

            FillDataset (transaction, commandType, commandText, dataSet, tableNames, null);    

        }

        

        /// <summary>

        /// 执行指定数据库事务的命令,映射数据表并填充数据集,指定参数.

        /// </summary>

        /// <remarks>

        /// 示例:  

        ///  FillDataset(trans, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, new SqlParameter("@prodid", 24));

        /// </remarks>

        /// <param>一个有效的连接事务</param>

        /// <param>命令类型 (存储过程,命令文本或其它)</param>

        /// <param>存储过程名称或T-SQL语句</param>

        /// <param>要填充结果集的DataSet实例</param>

        /// <param>表映射的数据表数组

        /// 用户定义的表名 (可有是实际的表名.)

        /// </param>

        /// <param>分配给命令的SqlParamter参数数组</param>

        public static void FillDataset(SqlTransaction transaction, CommandType commandType, 

            string commandText, DataSet dataSet, string[] tableNames,

            params SqlParameter[] commandParameters)

        {

            FillDataset(transaction.Connection, transaction, commandType, commandText, dataSet, tableNames, commandParameters);

        }

        

        /// <summary>

        /// 执行指定数据库事务的命令,映射数据表并填充数据集,指定存储过程参数值.

        /// </summary>

        /// <remarks>

        /// 此方法不提供访问存储过程输出参数和返回值参数.

        /// 

        /// 示例:  

        ///  FillDataset(trans, "GetOrders", ds, new string[]{"orders"}, 24, 36);

        /// </remarks>

        /// <param>一个有效的连接事务</param>

        /// <param>存储过程名称</param>

        /// <param>要填充结果集的DataSet实例</param>

        /// <param>表映射的数据表数组

        /// 用户定义的表名 (可有是实际的表名.)

        /// </param>

        /// <param>分配给存储过程输入参数的对象数组</param>

        public static void FillDataset(SqlTransaction transaction, string spName,

            DataSet dataSet, string[] tableNames,

            params object[] parameterValues) 

        {

            if( transaction == null ) throw new ArgumentNullException( "transaction" );

            if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );

            if( dataSet == null ) throw new ArgumentNullException( "dataSet" );

            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // 如果有参数值

            if ((parameterValues != null) && (parameterValues.Length > 0)) 

            {

                // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()

                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                // 给存储过程参数赋值

                AssignParameterValues(commandParameters, parameterValues);

                // 调用重载方法

                FillDataset(transaction, CommandType.StoredProcedure, spName, dataSet, tableNames, commandParameters);

            }

            else 

            {

                // 没有参数值

                FillDataset(transaction, CommandType.StoredProcedure, spName, dataSet, tableNames);

            }    

        }

        

        /// <summary>

        /// [私有方法][内部调用]执行指定数据库连接对象/事务的命令,映射数据表并填充数据集,DataSet/TableNames/SqlParameters.

        /// </summary>

        /// <remarks>

        /// 示例:  

        ///  FillDataset(conn, trans, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, new SqlParameter("@prodid", 24));

        /// </remarks>

        /// <param>一个有效的数据库连接对象</param>

        /// <param>一个有效的连接事务</param>

        /// <param>命令类型 (存储过程,命令文本或其它)</param>

        /// <param>存储过程名称或T-SQL语句</param>

        /// <param>要填充结果集的DataSet实例</param>

        /// <param>表映射的数据表数组

        /// 用户定义的表名 (可有是实际的表名.)

        /// </param>

        /// <param>分配给命令的SqlParamter参数数组</param>

        private static void FillDataset(SqlConnection connection, SqlTransaction transaction, CommandType commandType, 

            string commandText, DataSet dataSet, string[] tableNames,

            params SqlParameter[] commandParameters)

        {

            if( connection == null ) throw new ArgumentNullException( "connection" );

            if( dataSet == null ) throw new ArgumentNullException( "dataSet" );

            // 创建SqlCommand命令,并进行预处理

            SqlCommand command = new SqlCommand();

            bool mustCloseConnection = false;

            PrepareCommand(command, connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection );

                

            // 执行命令

            using( SqlDataAdapter dataAdapter = new SqlDataAdapter(command) )

            {

                

                // 追加表映射

                if (tableNames != null && tableNames.Length > 0)

                {

                    string tableName = "Table";

                    for (int index=0; index < tableNames.Length; index++)

                    {

                        if( tableNames[index] == null || tableNames[index].Length == 0 ) throw new ArgumentException( "The tableNames parameter must contain a list of tables, a value was provided as null or empty string.", "tableNames" );

                        dataAdapter.TableMappings.Add(tableName, tableNames[index]);

                        tableName += (index + 1).ToString();

                    }

                }

                

                // 填充数据集使用默认表名称

                dataAdapter.Fill(dataSet);

                // 清除参数,以便再次使用.

                command.Parameters.Clear();

            }

            if( mustCloseConnection )

                connection.Close();

        }

        #endregion

        

        #region UpdateDataset 更新数据集

        /// <summary>

        /// 执行数据集更新到数据库,指定inserted, updated, or deleted命令.

        /// </summary>

        /// <remarks>

        /// 示例:  

        ///  UpdateDataset(conn, insertCommand, deleteCommand, updateCommand, dataSet, "Order");

        /// </remarks>

        /// <param>[追加记录]一个有效的T-SQL语句或存储过程</param>

        /// <param>[删除记录]一个有效的T-SQL语句或存储过程</param>

        /// <param>[更新记录]一个有效的T-SQL语句或存储过程</param>

        /// <param>要更新到数据库的DataSet</param>

        /// <param>要更新到数据库的DataTable</param>

        public static void UpdateDataset(SqlCommand insertCommand, SqlCommand deleteCommand, SqlCommand updateCommand, DataSet dataSet, string tableName)

        {

            if( insertCommand == null ) throw new ArgumentNullException( "insertCommand" );

            if( deleteCommand == null ) throw new ArgumentNullException( "deleteCommand" );

            if( updateCommand == null ) throw new ArgumentNullException( "updateCommand" );

            if( tableName == null || tableName.Length == 0 ) throw new ArgumentNullException( "tableName" ); 

            // 创建SqlDataAdapter,当操作完成后释放.

            using (SqlDataAdapter dataAdapter = new SqlDataAdapter())

            {

                // 设置数据适配器命令

                dataAdapter.UpdateCommand = updateCommand;

                dataAdapter.InsertCommand = insertCommand;

                dataAdapter.DeleteCommand = deleteCommand;

                // 更新数据集改变到数据库

                dataAdapter.Update (dataSet, tableName); 

                // 提交所有改变到数据集.

                dataSet.AcceptChanges();

            }

        }

        #endregion

            

        #region CreateCommand 创建一条SqlCommand命令

        /// <summary>

        /// 创建SqlCommand命令,指定数据库连接对象,存储过程名和参数.

        /// </summary>

        /// <remarks>

        /// 示例:  

        ///  SqlCommand command = CreateCommand(conn, "AddCustomer", "CustomerID", "CustomerName");

        /// </remarks>

        /// <param>一个有效的数据库连接对象</param>

        /// <param>存储过程名称</param>

        /// <param>源表的列名称数组</param>

        /// <returns>返回SqlCommand命令</returns>

        public static SqlCommand CreateCommand(SqlConnection connection, string spName, params string[] sourceColumns) 

        {

            if( connection == null ) throw new ArgumentNullException( "connection" );

            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // 创建命令

            SqlCommand cmd = new SqlCommand( spName, connection );

            cmd.CommandType = CommandType.StoredProcedure;

            // 如果有参数值

            if ((sourceColumns != null) && (sourceColumns.Length > 0)) 

            {

                // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()

                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                // 将源表的列到映射到DataSet命令中.

                for (int index=0; index < sourceColumns.Length; index++)

                    commandParameters[index].SourceColumn = sourceColumns[index];

                // Attach the discovered parameters to the SqlCommand object

                AttachParameters (cmd, commandParameters);

            }

            return cmd;

        }

        #endregion

            

        #region ExecuteNonQueryTypedParams 类型化参数(DataRow)

        /// <summary>

        /// 执行指定连接数据库连接字符串的存储过程,使用DataRow做为参数值,返回受影响的行数.

        /// </summary>

        /// <param>一个有效的数据库连接字符串</param>

        /// <param>存储过程名称</param>

        /// <param>使用DataRow作为参数值</param>

        /// <returns>返回影响的行数</returns>

        public static int ExecuteNonQueryTypedParams(String connectionString, String spName, DataRow dataRow)

        {

            if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );

            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            

            // 如果row有值,存储过程必须初始化.

            if (dataRow != null && dataRow.ItemArray.Length > 0)

            {

                // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()

                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                

                // 分配参数值

                AssignParameterValues(commandParameters, dataRow);

                                

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

            }

            else

            {

                return SqlHelper.ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName);

            }

        }

        

        /// <summary>

        /// 执行指定连接数据库连接对象的存储过程,使用DataRow做为参数值,返回受影响的行数.

        /// </summary>

        /// <param>一个有效的数据库连接对象</param>

        /// <param>存储过程名称</param>

        /// <param>使用DataRow作为参数值</param>

        /// <returns>返回影响的行数</returns>

        public static int ExecuteNonQueryTypedParams(SqlConnection connection, String spName, DataRow dataRow)

        {

            if( connection == null ) throw new ArgumentNullException( "connection" );

            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // 如果row有值,存储过程必须初始化.

            if (dataRow != null && dataRow.ItemArray.Length > 0)

            {

                // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()

                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                

                // 分配参数值

                AssignParameterValues(commandParameters, dataRow);

                                

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

            }

            else

            {

                return SqlHelper.ExecuteNonQuery(connection, CommandType.StoredProcedure, spName);

            }

        }

        

        /// <summary>

        /// 执行指定连接数据库事物的存储过程,使用DataRow做为参数值,返回受影响的行数.

        /// </summary>

        /// <param>一个有效的连接事务 object</param>

        /// <param>存储过程名称</param>

        /// <param>使用DataRow作为参数值</param>

        /// <returns>返回影响的行数</returns>

        public static int ExecuteNonQueryTypedParams(SqlTransaction transaction, String spName, DataRow dataRow)

        {

            if( transaction == null ) throw new ArgumentNullException( "transaction" );

            if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );

            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // Sf the row has values, the store procedure parameters must be initialized

            if (dataRow != null && dataRow.ItemArray.Length > 0)

            {

                // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()

                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                

                // 分配参数值

                AssignParameterValues(commandParameters, dataRow);

                                

                return SqlHelper.ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName, commandParameters);

            }

            else

            {

                return SqlHelper.ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName);

            }

        }

        #endregion

            

        #region ExecuteDatasetTypedParams 类型化参数(DataRow)

        /// <summary>

        /// 执行指定连接数据库连接字符串的存储过程,使用DataRow做为参数值,返回DataSet.

        /// </summary>

        /// <param>一个有效的数据库连接字符串</param>

        /// <param>存储过程名称</param>

        /// <param>使用DataRow作为参数值</param>

        /// <returns>返回一个包含结果集的DataSet.</returns>

        public static DataSet ExecuteDatasetTypedParams(string connectionString, String spName, DataRow dataRow)

        {

            if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );

            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            //如果row有值,存储过程必须初始化.

            if ( dataRow != null && dataRow.ItemArray.Length > 0)

            {

                // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()

                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                

                // 分配参数值

                AssignParameterValues(commandParameters, dataRow);

                

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

            }

            else

            {

                return SqlHelper.ExecuteDataset(connectionString, CommandType.StoredProcedure, spName);

            }

        }

        

        /// <summary>

        /// 执行指定连接数据库连接对象的存储过程,使用DataRow做为参数值,返回DataSet.

        /// </summary>

        /// <param>一个有效的数据库连接对象</param>

        /// <param>存储过程名称</param>

        /// <param>使用DataRow作为参数值</param>

        /// <returns>返回一个包含结果集的DataSet.</returns>

        /// 

        public static DataSet ExecuteDatasetTypedParams(SqlConnection connection, String spName, DataRow dataRow)

        {

            if( connection == null ) throw new ArgumentNullException( "connection" );

            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // 如果row有值,存储过程必须初始化.

            if( dataRow != null && dataRow.ItemArray.Length > 0)

            {

                // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()

                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                

                // 分配参数值

                AssignParameterValues(commandParameters, dataRow);

                

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

            }

            else

            {

                return SqlHelper.ExecuteDataset(connection, CommandType.StoredProcedure, spName);

            }

        }

        

        /// <summary>

        /// 执行指定连接数据库事务的存储过程,使用DataRow做为参数值,返回DataSet.

        /// </summary>

        /// <param>一个有效的连接事务 object</param>

        /// <param>存储过程名称</param>

        /// <param>使用DataRow作为参数值</param>

        /// <returns>返回一个包含结果集的DataSet.</returns>

        public static DataSet ExecuteDatasetTypedParams(SqlTransaction transaction, String spName, DataRow dataRow)

        {

            if( transaction == null ) throw new ArgumentNullException( "transaction" );

            if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );

            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // 如果row有值,存储过程必须初始化.

            if( dataRow != null && dataRow.ItemArray.Length > 0)

            {

                // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()

                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                

                // 分配参数值

                AssignParameterValues(commandParameters, dataRow);

                

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

            }

            else

            {

                return SqlHelper.ExecuteDataset(transaction, CommandType.StoredProcedure, spName);

            }

        }

        #endregion

            

        #region ExecuteReaderTypedParams 类型化参数(DataRow)

        /// <summary>

        /// 执行指定连接数据库连接字符串的存储过程,使用DataRow做为参数值,返回DataReader.

        /// </summary>

        /// <param>一个有效的数据库连接字符串</param>

        /// <param>存储过程名称</param>

        /// <param>使用DataRow作为参数值</param>

        /// <returns>返回包含结果集的SqlDataReader</returns>

        public static SqlDataReader ExecuteReaderTypedParams(String connectionString, String spName, DataRow dataRow)

        {

            if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );

            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            

            // 如果row有值,存储过程必须初始化.

            if ( dataRow != null && dataRow.ItemArray.Length > 0 )

            {

                // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()

                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                

                // 分配参数值

                AssignParameterValues(commandParameters, dataRow);

                

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

            }

            else

            {

                return SqlHelper.ExecuteReader(connectionString, CommandType.StoredProcedure, spName);

            }

        }

                

        /// <summary>

        /// 执行指定连接数据库连接对象的存储过程,使用DataRow做为参数值,返回DataReader.

        /// </summary>

        /// <param>一个有效的数据库连接对象</param>

        /// <param>存储过程名称</param>

        /// <param>使用DataRow作为参数值</param>

        /// <returns>返回包含结果集的SqlDataReader</returns>

        public static SqlDataReader ExecuteReaderTypedParams(SqlConnection connection, String spName, DataRow dataRow)

        {

            if( connection == null ) throw new ArgumentNullException( "connection" );

            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // 如果row有值,存储过程必须初始化.

            if( dataRow != null && dataRow.ItemArray.Length > 0)

            {

                // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()

                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                

                // 分配参数值

                AssignParameterValues(commandParameters, dataRow);

                

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

            }

            else

            {

                return SqlHelper.ExecuteReader(connection, CommandType.StoredProcedure, spName);

            }

        }

        

        /// <summary>

        /// 执行指定连接数据库事物的存储过程,使用DataRow做为参数值,返回DataReader.

        /// </summary>

        /// <param>一个有效的连接事务 object</param>

        /// <param>存储过程名称</param>

        /// <param>使用DataRow作为参数值</param>

        /// <returns>返回包含结果集的SqlDataReader</returns>

        public static SqlDataReader ExecuteReaderTypedParams(SqlTransaction transaction, String spName, DataRow dataRow)

        {

            if( transaction == null ) throw new ArgumentNullException( "transaction" );

            if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );

            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // 如果row有值,存储过程必须初始化.

            if( dataRow != null && dataRow.ItemArray.Length > 0 )

            {

                // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()

                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                

                // 分配参数值

                AssignParameterValues(commandParameters, dataRow);

                

                return SqlHelper.ExecuteReader(transaction, CommandType.StoredProcedure, spName, commandParameters);

            }

            else

            {

                return SqlHelper.ExecuteReader(transaction, CommandType.StoredProcedure, spName);

            }

        }

        #endregion

            

        #region ExecuteScalarTypedParams 类型化参数(DataRow)

        /// <summary>

        /// 执行指定连接数据库连接字符串的存储过程,使用DataRow做为参数值,返回结果集中的第一行第一列.

        /// </summary>

        /// <param>一个有效的数据库连接字符串</param>

        /// <param>存储过程名称</param>

        /// <param>使用DataRow作为参数值</param>

        /// <returns>返回结果集中的第一行第一列</returns>

        public static object ExecuteScalarTypedParams(String connectionString, String spName, DataRow dataRow)

        {

            if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );

            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            

            // 如果row有值,存储过程必须初始化.

            if( dataRow != null && dataRow.ItemArray.Length > 0)

            {

                // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()

                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                

                // 分配参数值

                AssignParameterValues(commandParameters, dataRow);

                

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

            }

            else

            {

                return SqlHelper.ExecuteScalar(connectionString, CommandType.StoredProcedure, spName);

            }

        }

        

        /// <summary>

        /// 执行指定连接数据库连接对象的存储过程,使用DataRow做为参数值,返回结果集中的第一行第一列.

        /// </summary>

        /// <param>一个有效的数据库连接对象</param>

        /// <param>存储过程名称</param>

        /// <param>使用DataRow作为参数值</param>

        /// <returns>返回结果集中的第一行第一列</returns>

        public static object ExecuteScalarTypedParams(SqlConnection connection, String spName, DataRow dataRow)

        {

            if( connection == null ) throw new ArgumentNullException( "connection" );

            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // 如果row有值,存储过程必须初始化.

            if( dataRow != null && dataRow.ItemArray.Length > 0)

            {

                // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()

                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                

                // 分配参数值

                AssignParameterValues(commandParameters, dataRow);

                

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

            }

            else

            {

                return SqlHelper.ExecuteScalar(connection, CommandType.StoredProcedure, spName);

            }

        }

        

        /// <summary>

        /// 执行指定连接数据库事务的存储过程,使用DataRow做为参数值,返回结果集中的第一行第一列.

        /// </summary>

        /// <param>一个有效的连接事务 object</param>

        /// <param>存储过程名称</param>

        /// <param>使用DataRow作为参数值</param>

        /// <returns>返回结果集中的第一行第一列</returns>

        public static object ExecuteScalarTypedParams(SqlTransaction transaction, String spName, DataRow dataRow)

        {

            if( transaction == null ) throw new ArgumentNullException( "transaction" );

            if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );

            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // 如果row有值,存储过程必须初始化.

            if( dataRow != null && dataRow.ItemArray.Length > 0)

            {

                // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()

                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                

                // 分配参数值

                AssignParameterValues(commandParameters, dataRow);

                

                return SqlHelper.ExecuteScalar(transaction, CommandType.StoredProcedure, spName, commandParameters);

            }

            else

            {

                return SqlHelper.ExecuteScalar(transaction, CommandType.StoredProcedure, spName);

            }

        }

        #endregion

            

        #region ExecuteXmlReaderTypedParams 类型化参数(DataRow)

        /// <summary>

        /// 执行指定连接数据库连接对象的存储过程,使用DataRow做为参数值,返回XmlReader类型的结果集.

        /// </summary>

        /// <param>一个有效的数据库连接对象</param>

        /// <param>存储过程名称</param>

        /// <param>使用DataRow作为参数值</param>

        /// <returns>返回XmlReader结果集对象.</returns>

        public static XmlReader ExecuteXmlReaderTypedParams(SqlConnection connection, String spName, DataRow dataRow)

        {

            if( connection == null ) throw new ArgumentNullException( "connection" );

            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // 如果row有值,存储过程必须初始化.

            if( dataRow != null && dataRow.ItemArray.Length > 0)

            {

                // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()

                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                

                // 分配参数值

                AssignParameterValues(commandParameters, dataRow);

                

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

            }

            else

            {

                return SqlHelper.ExecuteXmlReader(connection, CommandType.StoredProcedure, spName);

            }

        }

        

        /// <summary>

        /// 执行指定连接数据库事务的存储过程,使用DataRow做为参数值,返回XmlReader类型的结果集.

        /// </summary>

        /// <param>一个有效的连接事务 object</param>

        /// <param>存储过程名称</param>

        /// <param>使用DataRow作为参数值</param>

        /// <returns>返回XmlReader结果集对象.</returns>

        public static XmlReader ExecuteXmlReaderTypedParams(SqlTransaction transaction, String spName, DataRow dataRow)

        {

            if( transaction == null ) throw new ArgumentNullException( "transaction" );

            if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );

            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // 如果row有值,存储过程必须初始化.

            if( dataRow != null && dataRow.ItemArray.Length > 0)

            {

                // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. ()

                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                

                // 分配参数值

                AssignParameterValues(commandParameters, dataRow);

                

                return SqlHelper.ExecuteXmlReader(transaction, CommandType.StoredProcedure, spName, commandParameters);

            }

            else

            {

                return SqlHelper.ExecuteXmlReader(transaction, CommandType.StoredProcedure, spName);

            }

        }

        #endregion

    }

    

    /// <summary>

    /// SqlHelperParameterCache提供缓存存储过程参数,并能够在运行时从存储过程中探索参数.

    /// </summary>

    public sealed class SqlHelperParameterCache

    {

        #region 私有方法,字段,构造函数

        // 私有构造函数,妨止类被实例化.

        private SqlHelperParameterCache() {}

        // 这个方法要注意

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

        /// <summary>

        /// 探索运行时的存储过程,返回SqlParameter参数数组.

        /// 初始化参数值为 DBNull.Value.

        /// </summary>

        /// <param>一个有效的数据库连接</param>

        /// <param>存储过程名称</param>

        /// <param>是否包含返回值参数</param>

        /// <returns>返回SqlParameter参数数组</returns>

        private static SqlParameter[] DiscoverSpParameterSet(SqlConnection connection, string spName, bool includeReturnValueParameter)

        {

            if( connection == null ) throw new ArgumentNullException( "connection" );

            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            SqlCommand cmd = new SqlCommand(spName, connection);

            cmd.CommandType = CommandType.StoredProcedure;

            connection.Open();

            // 检索cmd指定的存储过程的参数信息,并填充到cmd的Parameters参数集中.

            SqlCommandBuilder.DeriveParameters(cmd);

            connection.Close();

            // 如果不包含返回值参数,将参数集中的每一个参数删除.

            if (!includeReturnValueParameter) 

            {

                cmd.Parameters.RemoveAt(0);

            }

                

            // 创建参数数组

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

            // 将cmd的Parameters参数集复制到discoveredParameters数组.

            cmd.Parameters.CopyTo(discoveredParameters, 0);

            // 初始化参数值为 DBNull.Value.

            foreach (SqlParameter discoveredParameter in discoveredParameters)

            {

                discoveredParameter.Value = DBNull.Value;

            }

            return discoveredParameters;

        }

        

        /// <summary>

        /// SqlParameter参数数组的深层拷贝.

        /// </summary>

        /// <param>原始参数数组</param>

        /// <returns>返回一个同样的参数数组</returns>

        private static SqlParameter[] CloneParameters(SqlParameter[] originalParameters)

        {

            SqlParameter[] clonedParameters = new SqlParameter[originalParameters.Length];

            for (int i = 0, j = originalParameters.Length; i < j; i++)

            {

                clonedParameters[i] = (SqlParameter)((ICloneable)originalParameters[i]).Clone();

            }

            return clonedParameters;

        }

        #endregion 私有方法,字段,构造函数结束

            

        #region 缓存方法

        /// <summary>

        /// 追加参数数组到缓存.

        /// </summary>

        /// <param>一个有效的数据库连接字符串</param>

        /// <param>存储过程名或SQL语句</param>

        /// <param>要缓存的参数数组</param>

        public static void CacheParameterSet(string connectionString, string commandText, params SqlParameter[] commandParameters)

        {

            if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );

            if( commandText == null || commandText.Length == 0 ) throw new ArgumentNullException( "commandText" );

            string hashKey = connectionString + ":" + commandText;

            paramCache[hashKey] = commandParameters;

        }

        

        /// <summary>

        /// 从缓存中获取参数数组.

        /// </summary>

        /// <param>一个有效的数据库连接字符</param>

        /// <param>存储过程名或SQL语句</param>

        /// <returns>参数数组</returns>

        public static SqlParameter[] GetCachedParameterSet(string connectionString, string commandText)

        {

            if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );

            if( commandText == null || commandText.Length == 0 ) throw new ArgumentNullException( "commandText" );

            string hashKey = connectionString + ":" + commandText;

            SqlParameter[] cachedParameters = paramCache[hashKey] as SqlParameter[];

            if (cachedParameters == null)

            {            

                return null;

            }

            else

            {

                return CloneParameters(cachedParameters);

            }

        }

        #endregion 缓存方法结束

            

        #region 检索指定的存储过程的参数集

        /// <summary>

        /// 返回指定的存储过程的参数集

        /// </summary>

        /// <remarks>

        /// 这个方法将查询数据库,并将信息存储到缓存.

        /// </remarks>

        /// <param>一个有效的数据库连接字符</param>

        /// <param>存储过程名</param>

        /// <returns>返回SqlParameter参数数组</returns>

        public static SqlParameter[] GetSpParameterSet(string connectionString, string spName)

        {

            return GetSpParameterSet(connectionString, spName, false);

        }

        

        /// <summary>

        /// 返回指定的存储过程的参数集

        /// </summary>

        /// <remarks>

        /// 这个方法将查询数据库,并将信息存储到缓存.

        /// </remarks>

        /// <param>一个有效的数据库连接字符.</param>

        /// <param>存储过程名</param>

        /// <param>是否包含返回值参数</param>

        /// <returns>返回SqlParameter参数数组</returns>

        public static SqlParameter[] GetSpParameterSet(string connectionString, string spName, bool includeReturnValueParameter)

        {

            if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );

            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            using(SqlConnection connection = new SqlConnection(connectionString))

            {

                return GetSpParameterSetInternal(connection, spName, includeReturnValueParameter);

            }

        }

        

        /// <summary>

        /// [内部]返回指定的存储过程的参数集(使用连接对象).

        /// </summary>

        /// <remarks>

        /// 这个方法将查询数据库,并将信息存储到缓存.

        /// </remarks>

        /// <param>一个有效的数据库连接字符</param>

        /// <param>存储过程名</param>

        /// <returns>返回SqlParameter参数数组</returns>

        internal static SqlParameter[] GetSpParameterSet(SqlConnection connection, string spName)

        {

            return GetSpParameterSet(connection, spName, false);

        }

        

        /// <summary>

        /// [内部]返回指定的存储过程的参数集(使用连接对象)

        /// </summary>

        /// <remarks>

        /// 这个方法将查询数据库,并将信息存储到缓存.

        /// </remarks>

        /// <param>一个有效的数据库连接对象</param>

        /// <param>存储过程名</param>

        /// <param>

        /// 是否包含返回值参数

        /// </param>

        /// <returns>返回SqlParameter参数数组</returns>

        internal static SqlParameter[] GetSpParameterSet(SqlConnection connection, string spName, bool includeReturnValueParameter)

        {

            if( connection == null ) throw new ArgumentNullException( "connection" );

            using (SqlConnection clonedConnection = (SqlConnection)((ICloneable)connection).Clone())

            {

                return GetSpParameterSetInternal(clonedConnection, spName, includeReturnValueParameter);

            }

        }

        

        /// <summary>

        /// [私有]返回指定的存储过程的参数集(使用连接对象)

        /// </summary>

        /// <param>一个有效的数据库连接对象</param>

        /// <param>存储过程名</param>

        /// <param>是否包含返回值参数</param>

        /// <returns>返回SqlParameter参数数组</returns>

        private static SqlParameter[] GetSpParameterSetInternal(SqlConnection connection, string spName, bool includeReturnValueParameter)

        {

            if( connection == null ) throw new ArgumentNullException( "connection" );

            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

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

            SqlParameter[] cachedParameters;

            

            cachedParameters = paramCache[hashKey] as SqlParameter[];

            if (cachedParameters == null)

            {    

                SqlParameter[] spParameters = DiscoverSpParameterSet(connection, spName, includeReturnValueParameter);

                paramCache[hashKey] = spParameters;

                cachedParameters = spParameters;

            }

            

            return CloneParameters(cachedParameters);

        }

        

        #endregion 参数集检索结束

    }

}

原文地址:https://www.cnblogs.com/xiaofengfeng/p/2157052.html