///

/// OleDbServer数据访问帮助类 ///

public sealed class OleDbHelper
{
public static string getACCESS07constr(string accessfilename, string thepassword = @"")
{
if (thepassword.Length == 0)
return @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source = " + (char)34 + accessfilename + (char)34;
else
{ return @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source =" + (char)34 + accessfilename + (char)34 + @";Persist Security Info=True;Jet OLEDB:Database password=" + (char)34 + thepassword + (char)34; }
}
public static string getACCESSconstr(string accessfilename, string thepassword = @"")
{
if (thepassword.Length == 0)
return @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source =" + (char)34 + accessfilename + (char)34;
else
return @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source =" + (char)34 + accessfilename + (char)34 + @";Persist Security Info=True;Jet OLEDB:Database password=" + (char)34 + thepassword + (char)34;
}
//private static string _connectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source =db1.accdb";//定义数据库连接参数";

    private static string \_connectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source =PlanDb.accdb";//定义数据库连接参数";

    #region 私有构造函数和方法

    private OleDbHelper() { }

    /// <summary>  
    /// 将OleDbParameter参数数组(参数值)分配给OleDbCommand命令.  
    /// 这个方法将给任何一个参数分配DBNull.Value;  
    /// 该操作将阻止默认值的使用.  
    /// </summary>  
    /// <param name="command">命令名</param>  
    /// <param name="commandParameters">OleDbParameters数组</param>  
    private static void AttachParameters(OleDbCommand command, OleDbParameter\[\] commandParameters)  
    {  
        if (command == null) throw new ArgumentNullException("command");  
        if (commandParameters != null)  
        {  
            foreach (OleDbParameter 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OleDbParameter参数数组.  
    /// </summary>  
    /// <param name="commandParameters">要分配值的OleDbParameter参数数组</param>  
    /// <param name="dataRow">将要分配给存储过程参数的DataRow</param>  
    private static void AssignParameterValues(OleDbParameter\[\] commandParameters, DataRow dataRow)  
    {  
        if ((commandParameters == null) || (dataRow == null))  
        {  
            return;  
        }

        int i = 0;  
        // 设置参数值  
        foreach (OleDbParameter 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OleDbParameter参数数组.  
    /// </summary>  
    /// <param name="commandParameters">要分配值的OleDbParameter参数数组</param>  
    /// <param name="parameterValues">将要分配给存储过程参数的对象数组</param>  
    private static void AssignParameterValues(OleDbParameter\[\] commandParameters, object\[\] parameterValues)  
    {  
        if ((commandParameters == null) || (parameterValues == null))  
        {  
            return;  
        }

        // 确保对象数组个数与参数个数匹配,如果不匹配,抛出一个异常.  
        if (commandParameters.Length != parameterValues.Length)  
        {  
            throw new ArgumentException("参数值个数与参数不匹配.");  
        }

        // 给参数赋值  
        for (int i = 0, j = commandParameters.Length; i < j; i++)  
        {  
            // If the current array value derives from IDbDataParameter, then assign its Value property  
            if (parameterValues\[i\] is IDbDataParameter)  
            {  
                IDbDataParameter paramInstance = (IDbDataParameter)parameterValues\[i\];  
                if (paramInstance.Value == null)  
                {  
                    commandParameters\[i\].Value = DBNull.Value;  
                }  
                else  
                {  
                    commandParameters\[i\].Value = paramInstance.Value;  
                }  
            }  
            else if (parameterValues\[i\] == null)  
            {  
                commandParameters\[i\].Value = DBNull.Value;  
            }  
            else  
            {  
                commandParameters\[i\].Value = parameterValues\[i\];  
            }  
        }  
    }

    /// <summary>  
    /// 预处理用户提供的命令,数据库连接/事务/命令类型/参数  
    /// </summary>  
    /// <param name="command">要处理的OleDbCommand</param>  
    /// <param name="connection">数据库连接</param>  
    /// <param name="transaction">一个有效的事务或者是null值</param>  
    /// <param name="commandType">命令类型 (存储过程,命令文本, 其它.)</param>  
    /// <param name="commandText">存储过程名或都T-SQL命令文本</param>  
    /// <param name="commandParameters">和命令相关联的OleDbParameter参数数组,如果没有参数为'null'</param>  
    /// <param name="mustCloseConnection"><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(OleDbCommand command, OleDbConnection connection, OleDbTransaction transaction, CommandType commandType, string commandText, OleDbParameter\[\] 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 数据库连接  
    /// <summary>  
    /// 一个有效的数据库连接字符串  
    /// </summary>  
    /// <returns></returns>  
    public static string GetConnString()  
    {  
        return \_connectionString;

    }  
    /// <summary>  
    /// 一个有效的数据库连接对象  
    /// </summary>  
    /// <returns></returns>  
    public static OleDbConnection GetConnection()  
    {  
        OleDbConnection Connection = new OleDbConnection(OleDbHelper.GetConnString());  
        return Connection;  
    }  
    #endregion

    #region ExecuteNonQuery命令

    /// <summary>  
    /// 执行指定连接字符串,类型的OleDbCommand.  
    /// </summary>  
    /// <remarks>  
    /// 示例:  
    ///  int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders");  
    /// </remarks>  
    /// <param name="connectionString">一个有效的数据库连接字符串</param>  
    /// <param name="commandType">命令类型 (存储过程,命令文本, 其它.)</param>  
    /// <param name="commandText">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, (OleDbParameter\[\])null);  
    }

    /// <summary>  
    /// 执行指定连接字符串,类型的OleDbCommand.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 OleDbParameter("@prodid", 24));  
    /// </remarks>  
    /// <param name="connectionString">一个有效的数据库连接字符串</param>  
    /// <param name="commandType">命令类型 (存储过程,命令文本, 其它.)</param>  
    /// <param name="commandText">存储过程名称或SQL语句</param>  
    /// <param name="commandParameters">OleDbParameter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 OleDbParameter\[\] commandParameters)  
    {  
        if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");

        using (OleDbConnection connection = new OleDbConnection(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 name="connectionString">一个有效的数据库连接字符串/param>  
    /// <param name="spName">存储过程名称</param>  
    /// <param name="parameterValues">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.  
            OleDbParameter\[\] commandParameters = OleDbHelperParameterCache.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 name="connection">一个有效的数据库连接对象</param>  
    /// <param name="commandType">命令类型(存储过程,命令文本或其它.)</param>  
    /// <param name="commandText">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(OleDbConnection connection, CommandType commandType, string commandText)  
    {  
        return ExecuteNonQuery(connection, commandType, commandText, (OleDbParameter\[\])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 OleDbParameter("@prodid", 24));  
    /// </remarks>  
    /// <param name="connection">一个有效的数据库连接对象</param>  
    /// <param name="commandType">命令类型(存储过程,命令文本或其它.)</param>  
    /// <param name="commandText">T存储过程名称或T-SQL语句</param>  
    /// <param name="commandParameters">OleDbParamter参数数组</param>  
    /// <returns>返回影响的行数</returns>  
    public static int ExecuteNonQuery(OleDbConnection connection, CommandType commandType, string commandText, params OleDbParameter\[\] commandParameters)  
    {  
        if (connection == null) throw new ArgumentNullException("connection");

        // 创建OleDbCommand命令,并进行预处理  
        OleDbCommand cmd = new OleDbCommand();  
        bool mustCloseConnection = false;  
        PrepareCommand(cmd, connection, (OleDbTransaction)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 name="connection">一个有效的数据库连接对象</param>  
    /// <param name="spName">存储过程名</param>  
    /// <param name="parameterValues">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(OleDbConnection 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  
            OleDbParameter\[\] commandParameters = OleDbHelperParameterCache.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OleDbCommand.  
    /// </summary>  
    /// <remarks>  
    /// 示例.:  
    ///  int result = ExecuteNonQuery(trans, CommandType.StoredProcedure, "PublishOrders");  
    /// </remarks>  
    /// <param name="transaction">一个有效的数据库连接对象</param>  
    /// <param name="commandType">命令类型(存储过程,命令文本或其它.)</param>  
    /// <param name="commandText">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(OleDbTransaction transaction, CommandType commandType, string commandText)  
    {  
        return ExecuteNonQuery(transaction, commandType, commandText, (OleDbParameter\[\])null);  
    }

    /// <summary>  
    /// 执行带事务的OleDbCommand(指定参数).  
    /// </summary>  
    /// <remarks>  
    /// 示例:  
    ///  int result = ExecuteNonQuery(trans, CommandType.StoredProcedure, "GetOrders", new OleDbParameter("@prodid", 24));  
    /// </remarks>  
    /// <param name="transaction">一个有效的数据库连接对象</param>  
    /// <param name="commandType">命令类型(存储过程,命令文本或其它.)</param>  
    /// <param name="commandText">存储过程名称或T-SQL语句</param>  
    /// <param name="commandParameters">OleDbParamter参数数组</param>  
    /// <returns>返回影响的行数</returns>  
    public static int ExecuteNonQuery(OleDbTransaction transaction, CommandType commandType, string commandText, params OleDbParameter\[\] 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  
        OleDbCommand cmd = new OleDbCommand();  
        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OleDbCommand(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 name="transaction">一个有效的数据库连接对象</param>  
    /// <param name="spName">存储过程名</param>  
    /// <param name="parameterValues">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(OleDbTransaction 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. ()  
            OleDbParameter\[\] commandParameters = OleDbHelperParameterCache.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 name="connectionString">一个有效的数据库连接字符串</param>  
    /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>  
    /// <param name="commandText">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, (OleDbParameter\[\])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 OleDbParameter("@prodid", 24));  
    /// </remarks>  
    /// <param name="connectionString">一个有效的数据库连接字符串</param>  
    /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>  
    /// <param name="commandText">存储过程名称或T-SQL语句</param>  
    /// <param name="commandParameters">OleDbParamters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 OleDbParameter\[\] 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 (OleDbConnection connection = new OleDbConnection(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 name="connectionString">一个有效的数据库连接字符串</param>  
    /// <param name="spName">存储过程名</param>  
    /// <param name="parameterValues">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  
            OleDbParameter\[\] commandParameters = OleDbHelperParameterCache.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 name="connection">一个有效的数据库连接对象</param>  
    /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>  
    /// <param name="commandText">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(OleDbConnection connection, CommandType commandType, string commandText)  
    {  
        return ExecuteDataset(connection, commandType, commandText, (OleDbParameter\[\])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 OleDbParameter("@prodid", 24));  
    /// </remarks>  
    /// <param name="connection">一个有效的数据库连接对象</param>  
    /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>  
    /// <param name="commandText">存储过程名或T-SQL语句</param>  
    /// <param name="commandParameters">OleDbParamter参数数组</param>  
    /// <returns>返回一个包含结果集的DataSet</returns>  
    public static DataSet ExecuteDataset(OleDbConnection connection, CommandType commandType, string commandText, params OleDbParameter\[\] commandParameters)  
    {  
        if (connection == null) throw new ArgumentNullException("connection");

        // 预处理  
        OleDbCommand cmd = new OleDbCommand();  
        bool mustCloseConnection = false;  
        PrepareCommand(cmd, connection, (OleDbTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection);

        // 创建OleDbDataAdapter和DataSet.  
        using (OleDbDataAdapter da = new OleDbDataAdapter(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 name="connection">一个有效的数据库连接对象</param>  
    /// <param name="spName">存储过程名</param>  
    /// <param name="parameterValues">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(OleDbConnection 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  
            OleDbParameter\[\] commandParameters = OleDbHelperParameterCache.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 name="transaction">事务</param>  
    /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>  
    /// <param name="commandText">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(OleDbTransaction transaction, CommandType commandType, string commandText)  
    {  
        return ExecuteDataset(transaction, commandType, commandText, (OleDbParameter\[\])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 OleDbParameter("@prodid", 24));  
    /// </remarks>  
    /// <param name="transaction">事务</param>  
    /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>  
    /// <param name="commandText">存储过程名或T-SQL语句</param>  
    /// <param name="commandParameters">OleDbParamter参数数组</param>  
    /// <returns>返回一个包含结果集的DataSet</returns>  
    public static DataSet ExecuteDataset(OleDbTransaction transaction, CommandType commandType, string commandText, params OleDbParameter\[\] 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  
        OleDbCommand cmd = new OleDbCommand();  
        bool mustCloseConnection = false;  
        PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);

        // 创建 DataAdapter & DataSet  
        using (OleDbDataAdapter da = new OleDbDataAdapter(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 name="transaction">事务</param>  
    /// <param name="spName">存储过程名</param>  
    /// <param name="parameterValues">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(OleDbTransaction 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  
            OleDbParameter\[\] commandParameters = OleDbHelperParameterCache.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OleDbHelper提供还是由调用者提供  
    /// </summary>  
    private enum OleDbConnectionOwnership  
    {  
        /// <summary>由OleDbHelper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OleDbHelper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 name="connection">一个有效的数据库连接对象</param>  
    /// <param name="transaction">一个有效的事务,或者为 'null'</param>  
    /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>  
    /// <param name="commandText">存储过程名或T-SQL语句</param>  
    /// <param name="commandParameters">OleDbParameters参数数组,如果没有参数则为'null'</param>  
    /// <param name="connectionOwnership">标识数据库连接对象是由调用者提供还是由OleDbHelper提供</param>  
    /// <returns>返回包含结果集的OleDbDataReader</returns>  
    private static OleDbDataReader ExecuteReader(OleDbConnection connection, OleDbTransaction transaction, CommandType commandType, string commandText, OleDbParameter\[\] commandParameters, OleDbConnectionOwnership connectionOwnership)  
    {  
        if (connection == null) throw new ArgumentNullException("connection");

        bool mustCloseConnection = false;  
        // 创建命令  
        OleDbCommand cmd = new OleDbCommand();  
        try  
        {  
            PrepareCommand(cmd, connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);

            // 创建数据阅读器  
            OleDbDataReader dataReader;

            if (connectionOwnership == OleDbConnectionOwnership.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 OleDbReader can磘 set its values.  
            // When this happen, the parameters can磘 be used again in other command.  
            bool canClear = true;  
            foreach (OleDbParameter 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:  
    ///  OleDbDataReader dr = ExecuteReader(connString, CommandType.StoredProcedure, "GetOrders");  
    /// </remarks>  
    /// <param name="connectionString">一个有效的数据库连接字符串</param>  
    /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>  
    /// <param name="commandText">存储过程名或T-SQL语句</param>  
    /// <returns>返回包含结果集的OleDbDataReader</returns>  
    public static OleDbDataReader ExecuteReader(string connectionString, CommandType commandType, string commandText)  
    {  
        return ExecuteReader(connectionString, commandType, commandText, (OleDbParameter\[\])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:  
    ///  OleDbDataReader dr = ExecuteReader(connString, CommandType.StoredProcedure, "GetOrders", new OleDbParameter("@prodid", 24));  
    /// </remarks>  
    /// <param name="connectionString">一个有效的数据库连接字符串</param>  
    /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>  
    /// <param name="commandText">存储过程名或T-SQL语句</param>  
    /// <param name="commandParameters">OleDbParamter参数数组(new OleDbParameter("@prodid", 24))</param>  
    /// <returns>返回包含结果集的OleDbDataReader</returns>  
    public static OleDbDataReader ExecuteReader(string connectionString, CommandType commandType, string commandText, params OleDbParameter\[\] commandParameters)  
    {  
        if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");  
        OleDbConnection connection = null;  
        try  
        {  
            connection = new OleDbConnection(connectionString);  
            connection.Open();

            return ExecuteReader(connection, null, commandType, commandText, commandParameters, OleDbConnectionOwnership.Internal);  
        }  
        catch  
        {  
            // If we fail to return the OleDbDatReader, 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:  
    ///  OleDbDataReader dr = ExecuteReader(connString, "GetOrders", 24, 36);  
    /// </remarks>  
    /// <param name="connectionString">一个有效的数据库连接字符串</param>  
    /// <param name="spName">存储过程名</param>  
    /// <param name="parameterValues">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OleDbDataReader</returns>  
    public static OleDbDataReader 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))  
        {  
            OleDbParameter\[\] commandParameters = OleDbHelperParameterCache.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:  
    ///  OleDbDataReader dr = ExecuteReader(conn, CommandType.StoredProcedure, "GetOrders");  
    /// </remarks>  
    /// <param name="connection">一个有效的数据库连接对象</param>  
    /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>  
    /// <param name="commandText">存储过程名或T-SQL语句</param>  
    /// <returns>返回包含结果集的OleDbDataReader</returns>  
    public static OleDbDataReader ExecuteReader(OleDbConnection connection, CommandType commandType, string commandText)  
    {  
        return ExecuteReader(connection, commandType, commandText, (OleDbParameter\[\])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:  
    ///  OleDbDataReader dr = ExecuteReader(conn, CommandType.StoredProcedure, "GetOrders", new OleDbParameter("@prodid", 24));  
    /// </remarks>  
    /// <param name="connection">一个有效的数据库连接对象</param>  
    /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>  
    /// <param name="commandText">命令类型 (存储过程,命令文本或其它)</param>  
    /// <param name="commandParameters">OleDbParamter参数数组</param>  
    /// <returns>返回包含结果集的OleDbDataReader</returns>  
    public static OleDbDataReader ExecuteReader(OleDbConnection connection, CommandType commandType, string commandText, params OleDbParameter\[\] commandParameters)  
    {  
        return ExecuteReader(connection, (OleDbTransaction)null, commandType, commandText, commandParameters, OleDbConnectionOwnership.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:  
    ///  OleDbDataReader dr = ExecuteReader(conn, "GetOrders", 24, 36);  
    /// </remarks>  
    /// <param name="connection">一个有效的数据库连接对象</param>  
    /// <param name="spName">T存储过程名</param>  
    /// <param name="parameterValues">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OleDbDataReader</returns>  
    public static OleDbDataReader ExecuteReader(OleDbConnection 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))  
        {  
            OleDbParameter\[\] commandParameters = OleDbHelperParameterCache.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:  
    ///  OleDbDataReader dr = ExecuteReader(trans, CommandType.StoredProcedure, "GetOrders");  
    /// </remarks>  
    /// <param name="transaction">一个有效的连接事务</param>  
    /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>  
    /// <param name="commandText">存储过程名称或T-SQL语句</param>  
    /// <returns>返回包含结果集的OleDbDataReader</returns>  
    public static OleDbDataReader ExecuteReader(OleDbTransaction transaction, CommandType commandType, string commandText)  
    {  
        return ExecuteReader(transaction, commandType, commandText, (OleDbParameter\[\])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:  
    ///   OleDbDataReader dr = ExecuteReader(trans, CommandType.StoredProcedure, "GetOrders", new OleDbParameter("@prodid", 24));  
    /// </remarks>  
    /// <param name="transaction">一个有效的连接事务</param>  
    /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>  
    /// <param name="commandText">存储过程名称或T-SQL语句</param>  
    /// <param name="commandParameters">分配给命令的OleDbParamter参数数组</param>  
    /// <returns>返回包含结果集的OleDbDataReader</returns>  
    public static OleDbDataReader ExecuteReader(OleDbTransaction transaction, CommandType commandType, string commandText, params OleDbParameter\[\] 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, OleDbConnectionOwnership.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:  
    ///  OleDbDataReader dr = ExecuteReader(trans, "GetOrders", 24, 36);  
    /// </remarks>  
    /// <param name="transaction">一个有效的连接事务</param>  
    /// <param name="spName">存储过程名称</param>  
    /// <param name="parameterValues">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OleDbDataReader</returns>  
    public static OleDbDataReader ExecuteReader(OleDbTransaction 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))  
        {  
            OleDbParameter\[\] commandParameters = OleDbHelperParameterCache.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 name="connectionString">一个有效的数据库连接字符串</param>  
    /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>  
    /// <param name="commandText">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, (OleDbParameter\[\])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 OleDbParameter("@prodid", 24));  
    /// </remarks>  
    /// <param name="connectionString">一个有效的数据库连接字符串</param>  
    /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>  
    /// <param name="commandText">存储过程名称或T-SQL语句</param>  
    /// <param name="commandParameters">分配给命令的OleDbParamter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 OleDbParameter\[\] 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 (OleDbConnection connection = new OleDbConnection(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 name="connectionString">一个有效的数据库连接字符串</param>  
    /// <param name="spName">存储过程名称</param>  
    /// <param name="parameterValues">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. ()  
            OleDbParameter\[\] commandParameters = OleDbHelperParameterCache.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 name="connection">一个有效的数据库连接对象</param>  
    /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>  
    /// <param name="commandText">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(OleDbConnection connection, CommandType commandType, string commandText)  
    {  
        // 执行参数为空的方法  
        return ExecuteScalar(connection, commandType, commandText, (OleDbParameter\[\])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 OleDbParameter("@prodid", 24));  
    /// </remarks>  
    /// <param name="connection">一个有效的数据库连接对象</param>  
    /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>  
    /// <param name="commandText">存储过程名称或T-SQL语句</param>  
    /// <param name="commandParameters">分配给命令的OleDbParamter参数数组</param>  
    /// <returns>返回结果集中的第一行第一列</returns>  
    public static object ExecuteScalar(OleDbConnection connection, CommandType commandType, string commandText, params OleDbParameter\[\] commandParameters)  
    {  
        if (connection == null) throw new ArgumentNullException("connection");

        // 创建OleDbCommand命令,并进行预处理  
        OleDbCommand cmd = new OleDbCommand();

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

        // 执行OleDbCommand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 name="connection">一个有效的数据库连接对象</param>  
    /// <param name="spName">存储过程名称</param>  
    /// <param name="parameterValues">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(OleDbConnection 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. ()  
            OleDbParameter\[\] commandParameters = OleDbHelperParameterCache.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 name="transaction">一个有效的连接事务</param>  
    /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>  
    /// <param name="commandText">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(OleDbTransaction transaction, CommandType commandType, string commandText)  
    {  
        // 执行参数为空的方法  
        return ExecuteScalar(transaction, commandType, commandText, (OleDbParameter\[\])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 OleDbParameter("@prodid", 24));  
    /// </remarks>  
    /// <param name="transaction">一个有效的连接事务</param>  
    /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>  
    /// <param name="commandText">存储过程名称或T-SQL语句</param>  
    /// <param name="commandParameters">分配给命令的OleDbParamter参数数组</param>  
    /// <returns>返回结果集中的第一行第一列</returns>  
    public static object ExecuteScalar(OleDbTransaction transaction, CommandType commandType, string commandText, params OleDbParameter\[\] 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OleDbCommand命令,并进行预处理  
        OleDbCommand cmd = new OleDbCommand();  
        bool mustCloseConnection = false;  
        PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);

        // 执行OleDbCommand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 name="transaction">一个有效的连接事务</param>  
    /// <param name="spName">存储过程名称</param>  
    /// <param name="parameterValues">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(OleDbTransaction 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 ()  
            OleDbParameter\[\] commandParameters = OleDbHelperParameterCache.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 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 name="connectionString">一个有效的数据库连接字符串</param>  
    /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>  
    /// <param name="commandText">存储过程名称或T-SQL语句</param>  
    /// <param name="dataSet">要填充结果集的DataSet实例</param>  
    /// <param name="tableNames">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 (OleDbConnection connection = new OleDbConnection(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 OleDbParameter("@prodid", 24));  
    /// </remarks>  
    /// <param name="connectionString">一个有效的数据库连接字符串</param>  
    /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>  
    /// <param name="commandText">存储过程名称或T-SQL语句</param>  
    /// <param name="commandParameters">分配给命令的OleDbParamter参数数组</param>  
    /// <param name="dataSet">要填充结果集的DataSet实例</param>  
    /// <param name="tableNames">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 OleDbParameter\[\] 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 (OleDbConnection connection = new OleDbConnection(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 name="connectionString">一个有效的数据库连接字符串</param>  
    /// <param name="spName">存储过程名称</param>  
    /// <param name="dataSet">要填充结果集的DataSet实例</param>  
    /// <param name="tableNames">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 name="parameterValues">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 (OleDbConnection connection = new OleDbConnection(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 name="connection">一个有效的数据库连接对象</param>  
    /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>  
    /// <param name="commandText">存储过程名称或T-SQL语句</param>  
    /// <param name="dataSet">要填充结果集的DataSet实例</param>  
    /// <param name="tableNames">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(OleDbConnection 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 OleDbParameter("@prodid", 24));  
    /// </remarks>  
    /// <param name="connection">一个有效的数据库连接对象</param>  
    /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>  
    /// <param name="commandText">存储过程名称或T-SQL语句</param>  
    /// <param name="dataSet">要填充结果集的DataSet实例</param>  
    /// <param name="tableNames">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 name="commandParameters">分配给命令的OleDbParamter参数数组</param>  
    public static void FillDataset(OleDbConnection connection, CommandType commandType,  
        string commandText, DataSet dataSet, string\[\] tableNames,  
        params OleDbParameter\[\] 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 name="connection">一个有效的数据库连接对象</param>  
    /// <param name="spName">存储过程名称</param>  
    /// <param name="dataSet">要填充结果集的DataSet实例</param>  
    /// <param name="tableNames">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 name="parameterValues">分配给存储过程输入参数的对象数组</param>  
    public static void FillDataset(OleDbConnection 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. ()  
            OleDbParameter\[\] commandParameters = OleDbHelperParameterCache.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 name="transaction">一个有效的连接事务</param>  
    /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>  
    /// <param name="commandText">存储过程名称或T-SQL语句</param>  
    /// <param name="dataSet">要填充结果集的DataSet实例</param>  
    /// <param name="tableNames">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(OleDbTransaction 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 OleDbParameter("@prodid", 24));  
    /// </remarks>  
    /// <param name="transaction">一个有效的连接事务</param>  
    /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>  
    /// <param name="commandText">存储过程名称或T-SQL语句</param>  
    /// <param name="dataSet">要填充结果集的DataSet实例</param>  
    /// <param name="tableNames">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 name="commandParameters">分配给命令的OleDbParamter参数数组</param>  
    public static void FillDataset(OleDbTransaction transaction, CommandType commandType,  
        string commandText, DataSet dataSet, string\[\] tableNames,  
        params OleDbParameter\[\] 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 name="transaction">一个有效的连接事务</param>  
    /// <param name="spName">存储过程名称</param>  
    /// <param name="dataSet">要填充结果集的DataSet实例</param>  
    /// <param name="tableNames">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 name="parameterValues">分配给存储过程输入参数的对象数组</param>  
    public static void FillDataset(OleDbTransaction 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. ()  
            OleDbParameter\[\] commandParameters = OleDbHelperParameterCache.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/OleDbParameters.  
    /// </summary>  
    /// <remarks>  
    /// 示例:  
    ///  FillDataset(conn, trans, CommandType.StoredProcedure, "GetOrders", ds, new string\[\] {"orders"}, new OleDbParameter("@prodid", 24));  
    /// </remarks>  
    /// <param name="connection">一个有效的数据库连接对象</param>  
    /// <param name="transaction">一个有效的连接事务</param>  
    /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param>  
    /// <param name="commandText">存储过程名称或T-SQL语句</param>  
    /// <param name="dataSet">要填充结果集的DataSet实例</param>  
    /// <param name="tableNames">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 name="commandParameters">分配给命令的OleDbParamter参数数组</param>  
    private static void FillDataset(OleDbConnection connection, OleDbTransaction transaction, CommandType commandType,  
        string commandText, DataSet dataSet, string\[\] tableNames,  
        params OleDbParameter\[\] commandParameters)  
    {  
        if (connection == null) throw new ArgumentNullException("connection");  
        if (dataSet == null) throw new ArgumentNullException("dataSet");

        // 创建OleDbCommand命令,并进行预处理  
        OleDbCommand command = new OleDbCommand();  
        bool mustCloseConnection = false;  
        PrepareCommand(command, connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);

        // 执行命令  
        using (OleDbDataAdapter dataAdapter = new OleDbDataAdapter(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 name="insertCommand">\[追加记录\]一个有效的T-SQL语句或存储过程</param>  
    /// <param name="deleteCommand">\[删除记录\]一个有效的T-SQL语句或存储过程</param>  
    /// <param name="updateCommand">\[更新记录\]一个有效的T-SQL语句或存储过程</param>  
    /// <param name="dataSet">要更新到数据库的DataSet</param>  
    /// <param name="tableName">要更新到数据库的DataTable</param>  
    public static void UpdateDataset(OleDbCommand insertCommand, OleDbCommand deleteCommand, OleDbCommand 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OleDbDataAdapter,当操作完成后释放.  
        using (OleDbDataAdapter dataAdapter = new OleDbDataAdapter())  
        {  
            // 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OleDbCommand命令  
    /// <summary>  
    /// 创建OleDbCommand命令,指定数据库连接对象,存储过程名和参数.  
    /// </summary>  
    /// <remarks>  
    /// 示例:  
    ///  OleDbCommand command = CreateCommand(conn, "AddCustomer", "CustomerID", "CustomerName");  
    /// </remarks>  
    /// <param name="connection">一个有效的数据库连接对象</param>  
    /// <param name="spName">存储过程名称</param>  
    /// <param name="sourceColumns">源表的列名称数组</param>  
    /// <returns>返回OleDbCommand命令</returns>  
    public static OleDbCommand CreateCommand(OleDbConnection 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  
        OleDbCommand cmd = new OleDbCommand(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. ()  
            OleDbParameter\[\] commandParameters = OleDbHelperParameterCache.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 OleDbCommand 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 name="connectionString">一个有效的数据库连接字符串</param>  
    /// <param name="spName">存储过程名称</param>  
    /// <param name="dataRow">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. ()  
            OleDbParameter\[\] commandParameters = OleDbHelperParameterCache.GetSpParameterSet(connectionString, spName);

            // 分配参数值  
            AssignParameterValues(commandParameters, dataRow);

            return OleDbHelper.ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName, commandParameters);  
        }  
        else  
        {  
            return OleDbHelper.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 name="connection">一个有效的数据库连接对象</param>  
    /// <param name="spName">存储过程名称</param>  
    /// <param name="dataRow">使用DataRow作为参数值</param>  
    /// <returns>返回影响的行数</returns>  
    public static int ExecuteNonQueryTypedParams(OleDbConnection 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. ()  
            OleDbParameter\[\] commandParameters = OleDbHelperParameterCache.GetSpParameterSet(connection, spName);

            // 分配参数值  
            AssignParameterValues(commandParameters, dataRow);

            return OleDbHelper.ExecuteNonQuery(connection, CommandType.StoredProcedure, spName, commandParameters);  
        }  
        else  
        {  
            return OleDbHelper.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 name="transaction">一个有效的连接事务 object</param>  
    /// <param name="spName">存储过程名称</param>  
    /// <param name="dataRow">使用DataRow作为参数值</param>  
    /// <returns>返回影响的行数</returns>  
    public static int ExecuteNonQueryTypedParams(OleDbTransaction 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. ()  
            OleDbParameter\[\] commandParameters = OleDbHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

            // 分配参数值  
            AssignParameterValues(commandParameters, dataRow);

            return OleDbHelper.ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName, commandParameters);  
        }  
        else  
        {  
            return OleDbHelper.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 name="connectionString">一个有效的数据库连接字符串</param>  
    /// <param name="spName">存储过程名称</param>  
    /// <param name="dataRow">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. ()  
            OleDbParameter\[\] commandParameters = OleDbHelperParameterCache.GetSpParameterSet(connectionString, spName);

            // 分配参数值  
            AssignParameterValues(commandParameters, dataRow);

            return OleDbHelper.ExecuteDataset(connectionString, CommandType.StoredProcedure, spName, commandParameters);  
        }  
        else  
        {  
            return OleDbHelper.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 name="connection">一个有效的数据库连接对象</param>  
    /// <param name="spName">存储过程名称</param>  
    /// <param name="dataRow">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(OleDbConnection 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. ()  
            OleDbParameter\[\] commandParameters = OleDbHelperParameterCache.GetSpParameterSet(connection, spName);

            // 分配参数值  
            AssignParameterValues(commandParameters, dataRow);

            return OleDbHelper.ExecuteDataset(connection, CommandType.StoredProcedure, spName, commandParameters);  
        }  
        else  
        {  
            return OleDbHelper.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 name="transaction">一个有效的连接事务 object</param>  
    /// <param name="spName">存储过程名称</param>  
    /// <param name="dataRow">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(OleDbTransaction 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. ()  
            OleDbParameter\[\] commandParameters = OleDbHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

            // 分配参数值  
            AssignParameterValues(commandParameters, dataRow);

            return OleDbHelper.ExecuteDataset(transaction, CommandType.StoredProcedure, spName, commandParameters);  
        }  
        else  
        {  
            return OleDbHelper.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 name="connectionString">一个有效的数据库连接字符串</param>  
    /// <param name="spName">存储过程名称</param>  
    /// <param name="dataRow">使用DataRow作为参数值</param>  
    /// <returns>返回包含结果集的OleDbDataReader</returns>  
    public static OleDbDataReader 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. ()  
            OleDbParameter\[\] commandParameters = OleDbHelperParameterCache.GetSpParameterSet(connectionString, spName);

            // 分配参数值  
            AssignParameterValues(commandParameters, dataRow);

            return OleDbHelper.ExecuteReader(connectionString, CommandType.StoredProcedure, spName, commandParameters);  
        }  
        else  
        {  
            return OleDbHelper.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 name="connection">一个有效的数据库连接对象</param>  
    /// <param name="spName">存储过程名称</param>  
    /// <param name="dataRow">使用DataRow作为参数值</param>  
    /// <returns>返回包含结果集的OleDbDataReader</returns>  
    public static OleDbDataReader ExecuteReaderTypedParams(OleDbConnection 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. ()  
            OleDbParameter\[\] commandParameters = OleDbHelperParameterCache.GetSpParameterSet(connection, spName);

            // 分配参数值  
            AssignParameterValues(commandParameters, dataRow);

            return OleDbHelper.ExecuteReader(connection, CommandType.StoredProcedure, spName, commandParameters);  
        }  
        else  
        {  
            return OleDbHelper.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 name="transaction">一个有效的连接事务 object</param>  
    /// <param name="spName">存储过程名称</param>  
    /// <param name="dataRow">使用DataRow作为参数值</param>  
    /// <returns>返回包含结果集的OleDbDataReader</returns>  
    public static OleDbDataReader ExecuteReaderTypedParams(OleDbTransaction 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. ()  
            OleDbParameter\[\] commandParameters = OleDbHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

            // 分配参数值  
            AssignParameterValues(commandParameters, dataRow);

            return OleDbHelper.ExecuteReader(transaction, CommandType.StoredProcedure, spName, commandParameters);  
        }  
        else  
        {  
            return OleDbHelper.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 name="connectionString">一个有效的数据库连接字符串</param>  
    /// <param name="spName">存储过程名称</param>  
    /// <param name="dataRow">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. ()  
            OleDbParameter\[\] commandParameters = OleDbHelperParameterCache.GetSpParameterSet(connectionString, spName);

            // 分配参数值  
            AssignParameterValues(commandParameters, dataRow);

            return OleDbHelper.ExecuteScalar(connectionString, CommandType.StoredProcedure, spName, commandParameters);  
        }  
        else  
        {  
            return OleDbHelper.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 name="connection">一个有效的数据库连接对象</param>  
    /// <param name="spName">存储过程名称</param>  
    /// <param name="dataRow">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(OleDbConnection 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. ()  
            OleDbParameter\[\] commandParameters = OleDbHelperParameterCache.GetSpParameterSet(connection, spName);

            // 分配参数值  
            AssignParameterValues(commandParameters, dataRow);

            return OleDbHelper.ExecuteScalar(connection, CommandType.StoredProcedure, spName, commandParameters);  
        }  
        else  
        {  
            return OleDbHelper.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 name="transaction">一个有效的连接事务 object</param>  
    /// <param name="spName">存储过程名称</param>  
    /// <param name="dataRow">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(OleDbTransaction 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. ()  
            OleDbParameter\[\] commandParameters = OleDbHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

            // 分配参数值  
            AssignParameterValues(commandParameters, dataRow);

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

}

/// <summary>  
/// OleDbHelperParameterCache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 OleDbHelperParameterCache  
{  
    #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 OleDbHelperParameterCache() { }

    // 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OleDbParameter参数数组.  
    /// 初始化参数值为 DBNull.Value.  
    /// </summary>  
    /// <param name="connection">一个有效的数据库连接</param>  
    /// <param name="spName">存储过程名称</param>  
    /// <param name="includeReturnValueParameter">是否包含返回值参数</param>  
    /// <returns>返回OleDbParameter参数数组</returns>  
    private static OleDbParameter\[\] DiscoverSpParameterSet(OleDbConnection connection, string spName, bool includeReturnValueParameter)  
    {  
        if (connection == null) throw new ArgumentNullException("connection");  
        if (spName == null || spName.Length == 0) throw new ArgumentNullException("spName");

        OleDbCommand cmd = new OleDbCommand(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.  
        OleDbCommandBuilder.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  
        OleDbParameter\[\] discoveredParameters = new OleDbParameter\[cmd.Parameters.Count\];  
        // 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 (OleDbParameter discoveredParameter in discoveredParameters)  
        {  
            discoveredParameter.Value = DBNull.Value;  
        }  
        return discoveredParameters;  
    }

    /// <summary>  
    /// OleDbParameter参数数组的深层拷贝.  
    /// </summary>  
    /// <param name="originalParameters">原始参数数组</param>  
    /// <returns>返回一个同样的参数数组</returns>  
    private static OleDbParameter\[\] CloneParameters(OleDbParameter\[\] originalParameters)  
    {  
        OleDbParameter\[\] clonedParameters = new OleDbParameter\[originalParameters.Length\];

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

        return clonedParameters;  
    }

    #endregion 私有方法,字段,构造函数结束

    #region 缓存方法

    /// <summary>  
    /// 追加参数数组到缓存.  
    /// </summary>  
    /// <param name="connectionString">一个有效的数据库连接字符串</param>  
    /// <param name="commandText">存储过程名或SQL语句</param>  
    /// <param name="commandParameters">要缓存的参数数组</param>  
    public static void CacheParameterSet(string connectionString, string commandText, params OleDbParameter\[\] 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 name="connectionString">一个有效的数据库连接字符</param>  
    /// <param name="commandText">存储过程名或SQL语句</param>  
    /// <returns>参数数组</returns>  
    public static OleDbParameter\[\] 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;

        OleDbParameter\[\] cachedParameters = paramCache\[hashKey\] as OleDbParameter\[\];  
        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 name="connectionString">一个有效的数据库连接字符</param>  
    /// <param name="spName">存储过程名</param>  
    /// <returns>返回OleDbParameter参数数组</returns>  
    public static OleDbParameter\[\] 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 name="connectionString">一个有效的数据库连接字符.</param>  
    /// <param name="spName">存储过程名</param>  
    /// <param name="includeReturnValueParameter">是否包含返回值参数</param>  
    /// <returns>返回OleDbParameter参数数组</returns>  
    public static OleDbParameter\[\] 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 (OleDbConnection connection = new OleDbConnection(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 name="connection">一个有效的数据库连接字符</param>  
    /// <param name="spName">存储过程名</param>  
    /// <returns>返回OleDbParameter参数数组</returns>  
    internal static OleDbParameter\[\] GetSpParameterSet(OleDbConnection 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 name="connection">一个有效的数据库连接对象</param>  
    /// <param name="spName">存储过程名</param>  
    /// <param name="includeReturnValueParameter">  
    /// 是否包含返回值参数  
    /// </param>  
    /// <returns>返回OleDbParameter参数数组</returns>  
    internal static OleDbParameter\[\] GetSpParameterSet(OleDbConnection connection, string spName, bool includeReturnValueParameter)  
    {  
        if (connection == null) throw new ArgumentNullException("connection");  
        using (OleDbConnection clonedConnection = (OleDbConnection)((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 name="connection">一个有效的数据库连接对象</param>  
    /// <param name="spName">存储过程名</param>  
    /// <param name="includeReturnValueParameter">是否包含返回值参数</param>  
    /// <returns>返回OleDbParameter参数数组</returns>  
    private static OleDbParameter\[\] GetSpParameterSetInternal(OleDbConnection 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" : "");

        OleDbParameter\[\] cachedParameters;

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

        return CloneParameters(cachedParameters);  
    }

    #endregion 参数集检索结束

}