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  • 微软官方的SQLHelper类(含完整中文注释)(转)

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

    里面的函数一堆,常用的就那几个,无非就是增删改查嘛,来看下几种常用的函数:

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

    使用方法介绍

    Web.config配置

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

    调用函数的写法

    1 sql = "UPDATE Student set Name = @Name WHERE Id = @Id";
    2 SqlHelper.ExecuteNonQuery(CommandType.Text, sql, new SqlParameter[]{
    3  new SqlParameter("@Name", name),
    4  new SqlParameter("@Id", id)
    5 });

    这样调用就比较简化,而且比较灵活

    using System;
    using System.Data;
    using System.Xml;
    using System.Data.SqlClient;
    using System.Collections;
    namespace myhelper
    {
        /// <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>SqlHelperSqlHelper
            /// <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 is IDbDataParameter)
                    {
                        IDbDataParameter paramInstance = (IDbDataParameter)parameterValues;
                        if( paramInstance.Value == null )
                        {
                            commandParameters.Value = DBNull.Value; 
                        }
                        else
                        {
                            commandParameters.Value = paramInstance.Value;
                        }
                    }
                    else if (parameterValues == null)
                    {
                        commandParameters.Value = DBNull.Value;
                    }
                    else
                    {
                        commandParameters.Value = parameterValues;
                    }
                }
            }
            
            /// <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 = (SqlParameter)((ICloneable)originalParameters).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
        }
    }
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  • 原文地址:https://www.cnblogs.com/wenjie0904/p/10090442.html
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