SqlHelper 幫助文檔及詳解--項目初步搭建

 

微軟SqlHelper類中文註釋和使用方法

相關連接:  http://blog.csdn.net/itmaxin/article/details/7609566



SqlHelper.cs是N年前微軟出品的一個使用ADO.Net方法對SQL Server數據庫進行操做的封裝類，隨後有高人根據這個類寫了DbHelper.cs以操做SQL Server以外的數據庫，然後微軟也發佈了Enterprise Library企業庫組件。可是對於剛開始學習ADO.Net/C#或者中小企業應用層面來講，根據SqlHelper.cs類作簡單的數據庫訪問層的東西已經足夠用了。Enterprise Library企業庫雖然十分的強大，可是入手和配置都不是那麼簡單，殺雞徹底不用宰牛刀。

其實這個很古老的類還有一個很值得學習的地方：C#中重載的使用。每一個查詢數據庫的方法都有8個左右的重載方法，對C#面向對象思想中的多態性不瞭解的，看過這些個重載方法基本上都會清清楚楚了。此外應該注意的是public sealed class SqlHelper{}：sealed修飾符修飾的類是封閉的類，是不能被繼承的。

和微軟發佈的SqlHelper.cs不一樣，爲了方便我把裏面的SqlHelperParameterCatch.cs單獨列出來了。下面的下載中還有OledbHelper.cs、OdbcHelper.cs和XMLHelper.cs可供使用，分別針對不一樣的數據庫類型。下面略微解析一下SqlHelper.cs這個類的使用方法，其中類內部使用的私有方法再也不介紹，由於公共方法的使用大同小異，因此就以最簡單的ExecuteNonQuery()方法做爲範例。
ASP.NET/C#語言:
下述代碼是ExecuteNonQuery()的9個重載方法。
前3個算是準備查詢。
[csharp] view plaincopy

    //#1-1  
    public static int ExecuteNonQuery(string connectionString, CommandType commandType, string commandText){}  
    //#1-2  
    public static int ExecuteNonQuery(string connectionString, CommandType commandType, string commandText,   
    params SqlParameter[] commandParameters){}  
    //#1-3  
    public static int ExecuteNonQuery(string connectionString, string spName, params object[] parameterValues){}  


中間3個是執行查詢。
[csharp] view plaincopy

    //#2-1  
    public static int ExecuteNonQuery(SqlConnection connection, CommandType commandType, string commandText){}  
    //#2-2  
    public static int ExecuteNonQuery(SqlConnection connection, CommandType commandType, string commandText,  
     params SqlParameter[] commandParameters){}  
    //#2-3  
    public static int ExecuteNonQuery(SqlConnection connection, string spName, params object[] parameterValues){}  


後面3個則是用於SQL事物查詢。
[csharp] view plaincopy

    //#3-1  
    public static int ExecuteNonQuery(SqlTransaction transaction, CommandType commandType, string commandText){}  
    //#3-2  
    public static int ExecuteNonQuery(SqlTransaction transaction, CommandType commandType, string commandText,  
     params SqlParameter[] commandParameters){}  
    //#3-3  
    public static int ExecuteNonQuery(SqlTransaction transaction, string spName, params object[] parameterValues){}  


再細分，

[csharp] view plaincopy

    //#2-1  
    public static int ExecuteNonQuery(SqlConnection connection, CommandType commandType,  
     string commandText){}  

執行的是無參數的SQL語句，而

[csharp] view plaincopy

    //#2-2  
    public static int ExecuteNonQuery(SqlConnection connection, CommandType commandType,   
    string commandText, params SqlParameter[] commandParameters){}  

執行的是包含參數數組的SQL語句（參數數組能夠爲空）。


[csharp] view plaincopy

    //#2-3  
    public static int ExecuteNonQuery(SqlConnection connection, string spName,   
    params object[] parameterValues){}  

執行的則是無返回值的存儲過程。

實際上，#1-1和#1-3

[csharp] view plaincopy

    //#1-1  
    public static int ExecuteNonQuery(string connectionString, CommandType commandType,  
     string commandText){}  
      
    //#1-3  
    public static int ExecuteNonQuery(string connectionString, string spName,  
     params object[] parameterValues){}  

重載是爲了方便無參數的SQL語句。


而#1-3和#2-3

[csharp] view plaincopy

    //#1-3  
    public static int ExecuteNonQuery(string connectionString, string spName,   
    params object[] parameterValues){}  

[csharp] view plaincopy

    //#2-3  
    public static int ExecuteNonQuery(SqlConnection connection, string spName,   
    params object[] parameterValues){}  

重載只是爲了方便調用存儲過程，他們的本質仍是和#1-2和#2-2

[csharp] view plaincopy

    //#1-2  
    public static int ExecuteNonQuery(string connectionString, CommandType commandType,  
     string commandText,   
    params SqlParameter[] commandParameters){}  

[csharp] view plaincopy

    //#2-2  
    public static int ExecuteNonQuery(SqlConnection connection, CommandType commandType,   
    string commandText,  
     params SqlParameter[] commandParameters){}  

同樣。下面是針對重載方法的一些簡單使用。

1. ExecuteNonQuery()執行無參數的SQL語句。
ASP.NET/C#語言:
[csharp] view plaincopy

    string sql = "INSERT INTO Customer(Country,Firstname,Lastname) VALUES('USA','Steven','Sun')";  
    if (SqlHelper.ExecuteNonQuery(SqlHelper.connectionString, CommandType.Text, sql) == 1)  
    {  
        Response.Write("添加成功！");  
    }  



能夠簡單的分析一下執行的過程：

    ExecuteNonQuery()方法根據參數不一樣將會首先重載#1-1，
    [csharp] view plaincopy
        //#1-1  
        public static int ExecuteNonQuery(string connectionString, CommandType commandType,  
         string commandText){}  
    在#1-1中設置參數數組爲null，既
    [csharp] view plaincopy
        SqlHelper.ExecuteNonQuery(SqlHelper.connectionString, CommandType.Text, sql,  
    [csharp] view plaincopy
         (SqlParameter[])null)。  
    這時候ExecuteNonQuery()方法根據參數不一樣將會首先重載#1-2，
    [csharp] view plaincopy
        //#1-2  
        public static int ExecuteNonQuery(string connectionString, CommandType commandType, string commandText,   
        params SqlParameter[] commandParameters){}  
    在#1-2中重載#2-2方法執行查詢。
    [csharp] view plaincopy
        //#2-2  
        public static int ExecuteNonQuery(SqlConnection connection, CommandType commandType,   
        string commandText, params SqlParameter[] commandParameters){}  
    在#2-2中首先要使用私有的PrepareCommand()方法把參數放入SqlCommand中，而後執行ADO.Net的ExecuteNonQuery()方法（這個是無參數的原始方法），執行成功則返回整數1。
    剩下的就是一些判斷和輸出的過程了。


也能夠本身寫一些別的方法驗證其餘重載方法的時候，在Visual Studio中按F11能夠逐語句的查看執行的過程，下面兩個方法的使用也是同樣的，因此就只貼代碼了。
2. ExecuteNonQuery()執行有參數數組的SQL語句。
ASP.NET/C#語言:
[csharp] view plaincopy

    //修改指定CustomerId的顧客的國籍  
    string sql = "UPDATE Customer SET Country=@Country WHERE CustomerId=@CustomerId";  
    SqlParameter[] param = new SqlParameter[]  
    {  
        new SqlParameter("@Version", SqlDbType.VarChar),  
        new SqlParameter("@CustomerId", SqlDbType.Int)  
    };  
    param[0].Value = "England";  
    param[1].Value = 5;  
    if (SqlHelper.ExecuteNonQuery(SqlHelper.connectionString, CommandType.Text, sql, param) == 1)  
    {  
        Response.Write("修改爲功！");  
    }  

3. ExecuteNonQuery()執行無返回值的存儲過程。
SQL Server語言:
[sql] view plaincopy

    CREATE PROCEDURE [dbo].[SP_ExecuteNonQuery]  
    AS  
    BEGIN  
    INSERT INTO Customer VALUES('Japan','Beautiful','Girl')  
    END  


ASP.NET/C#語言：
[csharp] view plaincopy

    if (SqlHelper.ExecuteNonQuery(SqlHelper.connectionString, "SP_ExecuteNonQuery") == 1)  
    {  
         Response.Write("執行無參數存儲過程成功");  
    }  



其餘方法都是相似的，這個類中咱們經常使用的方法以下：

    ExecuteNonQuery(): 執行簡單的無返回值的查詢。
    ExecuteDataset(): 返回Dataset的查詢，至關於返回一個數組。
    ExecuteReader(): 使用DataReader讀取數據。（注：少許數據的狀況下使用SqlDataReader的效率高於使用Dataset）
    ExecuteScalar(): 返回結果集中的第一行第一列，至關於返回單個值。

其餘的方法使用的較少，就不介紹了。強烈建議使用Visual Studio 2010調試這些程序，下面是這幾個類的下載地址，若有問題，歡迎和我一塊兒探討。


在原文的基礎上稍有改動。

參考自：「一我的飛」博客。

View Code

 

SqlServer數據訪問幫助類---SqlHelper(帶詳細中文註釋)

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

namespace hkszyy
{
 /// <summary>
 /// SqlServer數據訪問幫助類
 /// </summary>
 public sealed class SqlHelper
 {
  #region 私有構造函數和方法

  private SqlHelper() {}

  /// <summary>
  /// 將SqlParameter參數數組(參數值)分配給SqlCommand命令.
  /// 這個方法將給任何一個參數分配DBNull.Value;
  /// 該操做將阻止默認值的使用.
  /// </summary>
  /// <param name="command">命令名</param>
  /// <param name="commandParameters">SqlParameters數組</param>
  private static void AttachParameters(SqlCommand command, SqlParameter[] commandParameters)
  {
   if( command == null ) throw new ArgumentNullException( "command" );
   if( commandParameters != null )
   {
    foreach (SqlParameter p in commandParameters)
    {
     if( p != null )
     {
      // 檢查未分配值的輸出參數,將其分配以DBNull.Value.
      if ( ( p.Direction == ParameterDirection.InputOutput || p.Direction == ParameterDirection.Input ) &&
       (p.Value == null))
      {
       p.Value = DBNull.Value;
      }
      command.Parameters.Add(p);
     }
    }
   }
  }

  /// <summary>
  /// 將DataRow類型的列值分配到SqlParameter參數數組.
  /// </summary>
  /// <param name="commandParameters">要分配值的SqlParameter參數數組</param>
  /// <param name="dataRow">將要分配給存儲過程參數的DataRow</param>
  private static void AssignParameterValues(SqlParameter[] commandParameters, DataRow dataRow)
  {
   if ((commandParameters == null) || (dataRow == null))
   {
    return;
   }

   int i = 0;
   // 設置參數值
   foreach(SqlParameter commandParameter in commandParameters)
   {
    // 建立參數名稱,若是不存在,只拋出一個異常.
    if( commandParameter.ParameterName == null ||
     commandParameter.ParameterName.Length <= 1 )
     throw new Exception(
      string.Format("請提供參數{0}一個有效的名稱{1}.", i, commandParameter.ParameterName ) );
    // 從dataRow的表中獲取爲參數數組中數組名稱的列的索引.
    // 若是存在和參數名稱相同的列,則將列值賦給當前名稱的參數.
    if (dataRow.Table.Columns.IndexOf(commandParameter.ParameterName.Substring(1)) != -1)
     commandParameter.Value = dataRow[commandParameter.ParameterName.Substring(1)];
    i++;
   }
  }

  /// <summary>
  /// 將一個對象數組分配給SqlParameter參數數組.
  /// </summary>
  /// <param name="commandParameters">要分配值的SqlParameter參數數組</param>
  /// <param name="parameterValues">將要分配給存儲過程參數的對象數組</param>
  private static void AssignParameterValues(SqlParameter[] commandParameters, object[] parameterValues)
  {
   if ((commandParameters == null) || (parameterValues == null))
   {
    return;
   }

   // 確保對象數組個數與參數個數匹配,若是不匹配,拋出一個異常.
   if (commandParameters.Length != parameterValues.Length)
   {
    throw new ArgumentException("參數值個數與參數不匹配.");
   }

   // 給參數賦值
   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>
  /// 預處理用戶提供的命令,數據庫鏈接/事務/命令類型/參數
  /// </summary>
  /// <param name="command">要處理的SqlCommand</param>
  /// <param name="connection">數據庫鏈接</param>
  /// <param name="transaction">一個有效的事務或者是null值</param>
  /// <param name="commandType">命令類型 (存儲過程,命令文本, 其它.)</param>
  /// <param name="commandText">存儲過程名或都T-SQL命令文本</param>
  /// <param name="commandParameters">和命令相關聯的SqlParameter參數數組,若是沒有參數爲'null'</param>
  /// <param name="mustCloseConnection"><c>true</c> 若是鏈接是打開的,則爲true,其它狀況下爲false.</param>
  private static void PrepareCommand(SqlCommand command, SqlConnection connection, SqlTransaction transaction, CommandType commandType, string commandText, SqlParameter[] commandParameters, out bool mustCloseConnection )
  {
   if( command == null ) throw new ArgumentNullException( "command" );
   if( commandText == null || commandText.Length == 0 ) throw new ArgumentNullException( "commandText" );

   // If the provided connection is not open, we will open it
   if (connection.State != ConnectionState.Open)
   {
    mustCloseConnection = true;
    connection.Open();
   }
   else
   {
    mustCloseConnection = false;
   }

   // 給命令分配一個數據庫鏈接.
   command.Connection = connection;

   // 設置命令文本(存儲過程名或SQL語句)
   command.CommandText = commandText;

   // 分配事務
   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;
   }

   // 設置命令類型.
   command.CommandType = commandType;

   // 分配命令參數
   if (commandParameters != null)
   {
    AttachParameters(command, commandParameters);
   }
   return;
  }

  #endregion 私有構造函數和方法結束

  #region ExecuteNonQuery命令

  /// <summary>
  /// 執行指定鏈接字符串,類型的SqlCommand.
  /// </summary>
  /// <remarks>
  /// 示例: 
  ///  int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders");
  /// </remarks>
  /// <param name="connectionString">一個有效的數據庫鏈接字符串</param>
  /// <param name="commandType">命令類型 (存儲過程,命令文本, 其它.)</param>
  /// <param name="commandText">存儲過程名稱或SQL語句</param>
  /// <returns>返回命令影響的行數</returns>
  public static int ExecuteNonQuery(string connectionString, CommandType commandType, string commandText)
  {
   return ExecuteNonQuery(connectionString, commandType, commandText, (SqlParameter[])null);
  }

  /// <summary>
  /// 執行指定鏈接字符串,類型的SqlCommand.若是沒有提供參數,不返回結果.
  /// </summary>
  /// <remarks>
  /// 示例: 
  ///  int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
  /// </remarks>
  /// <param name="connectionString">一個有效的數據庫鏈接字符串</param>
  /// <param name="commandType">命令類型 (存儲過程,命令文本, 其它.)</param>
  /// <param name="commandText">存儲過程名稱或SQL語句</param>
  /// <param name="commandParameters">SqlParameter參數數組</param>
  /// <returns>返回命令影響的行數</returns>
  public static int ExecuteNonQuery(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
  {
   if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );

   using (SqlConnection connection = new SqlConnection(connectionString))
   {
    connection.Open();

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

  /// <summary>
  /// 執行指定鏈接字符串的存儲過程,將對象數組的值賦給存儲過程參數,
  /// 此方法須要在參數緩存方法中探索參數並生成參數.
  /// </summary>
  /// <remarks>
  /// 這個方法沒有提供訪問輸出參數和返回值.
  /// 示例: 
  ///  int result = ExecuteNonQuery(connString, "PublishOrders", 24, 36);
  /// </remarks>
  /// <param name="connectionString">一個有效的數據庫鏈接字符串/param>
  /// <param name="spName">存儲過程名稱</param>
  /// <param name="parameterValues">分配到存儲過程輸入參數的對象數組</param>
  /// <returns>返回受影響的行數</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" );

   // 若是存在參數值
   if ((parameterValues != null) && (parameterValues.Length > 0))
   {
    // 從探索存儲過程參數(加載到緩存)並分配給存儲過程參數數組.
    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

    // 給存儲過程參數賦值
    AssignParameterValues(commandParameters, parameterValues);

    return ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName, commandParameters);
   }
   else
   {
    // 沒有參數狀況下
    return ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName);
   }
  }

  /// <summary>
  /// 執行指定數據庫鏈接對象的命令
  /// </summary>
  /// <remarks>
  /// 示例: 
  ///  int result = ExecuteNonQuery(conn, CommandType.StoredProcedure, "PublishOrders");
  /// </remarks>
  /// <param name="connection">一個有效的數據庫鏈接對象</param>
  /// <param name="commandType">命令類型(存儲過程,命令文本或其它.)</param>
  /// <param name="commandText">存儲過程名稱或T-SQL語句</param>
  /// <returns>返回影響的行數</returns>
  public static int ExecuteNonQuery(SqlConnection connection, CommandType commandType, string commandText)
  {
   return ExecuteNonQuery(connection, commandType, commandText, (SqlParameter[])null);
  }

  /// <summary>
  /// 執行指定數據庫鏈接對象的命令
  /// </summary>
  /// <remarks>
  /// 示例: 
  ///  int result = ExecuteNonQuery(conn, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
  /// </remarks>
  /// <param name="connection">一個有效的數據庫鏈接對象</param>
  /// <param name="commandType">命令類型(存儲過程,命令文本或其它.)</param>
  /// <param name="commandText">T存儲過程名稱或T-SQL語句</param>
  /// <param name="commandParameters">SqlParamter參數數組</param>
  /// <returns>返回影響的行數</returns>
  public static int ExecuteNonQuery(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
  {   
   if( connection == null ) throw new ArgumentNullException( "connection" );

   // 建立SqlCommand命令,並進行預處理
   SqlCommand cmd = new SqlCommand();
   bool mustCloseConnection = false;
   PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection );
           
   // Finally, execute the command
   int retval = cmd.ExecuteNonQuery();
           
   // 清除參數,以便再次使用.
   cmd.Parameters.Clear();
   if( mustCloseConnection )
    connection.Close();
   return retval;
  }

  /// <summary>
  /// 執行指定數據庫鏈接對象的命令,將對象數組的值賦給存儲過程參數.
  /// </summary>
  /// <remarks>
  /// 此方法不提供訪問存儲過程輸出參數和返回值
  /// 示例: 
  ///  int result = ExecuteNonQuery(conn, "PublishOrders", 24, 36);
  /// </remarks>
  /// <param name="connection">一個有效的數據庫鏈接對象</param>
  /// <param name="spName">存儲過程名</param>
  /// <param name="parameterValues">分配給存儲過程輸入參數的對象數組</param>
  /// <returns>返回影響的行數</returns>
  public static int ExecuteNonQuery(SqlConnection connection, string spName, params object[] parameterValues)
  {
   if( connection == null ) throw new ArgumentNullException( "connection" );
   if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

   // 若是有參數值
   if ((parameterValues != null) && (parameterValues.Length > 0))
   {
    // 從緩存中加載存儲過程參數
    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

    // 給存儲過程分配參數值
    AssignParameterValues(commandParameters, parameterValues);

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

  /// <summary>
  /// 執行帶事務的SqlCommand.
  /// </summary>
  /// <remarks>
  /// 示例.: 
  ///  int result = ExecuteNonQuery(trans, CommandType.StoredProcedure, "PublishOrders");
  /// </remarks>
  /// <param name="transaction">一個有效的數據庫鏈接對象</param>
  /// <param name="commandType">命令類型(存儲過程,命令文本或其它.)</param>
  /// <param name="commandText">存儲過程名稱或T-SQL語句</param>
  /// <returns>返回影響的行數/returns>
  public static int ExecuteNonQuery(SqlTransaction transaction, CommandType commandType, string commandText)
  {
   return ExecuteNonQuery(transaction, commandType, commandText, (SqlParameter[])null);
  }

  /// <summary>
  /// 執行帶事務的SqlCommand(指定參數).
  /// </summary>
  /// <remarks>
  /// 示例: 
  ///  int result = ExecuteNonQuery(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
  /// </remarks>
  /// <param name="transaction">一個有效的數據庫鏈接對象</param>
  /// <param name="commandType">命令類型(存儲過程,命令文本或其它.)</param>
  /// <param name="commandText">存儲過程名稱或T-SQL語句</param>
  /// <param name="commandParameters">SqlParamter參數數組</param>
  /// <returns>返回影響的行數</returns>
  public static int ExecuteNonQuery(SqlTransaction transaction, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
  {
   if( transaction == null ) throw new ArgumentNullException( "transaction" );
   if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );

   // 預處理
   SqlCommand cmd = new SqlCommand();
   bool mustCloseConnection = false;
   PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection );
               
   // 執行
   int retval = cmd.ExecuteNonQuery();
               
   // 清除參數集,以便再次使用.
   cmd.Parameters.Clear();
   return retval;
  }

  /// <summary>
  /// 執行帶事務的SqlCommand(指定參數值).
  /// </summary>
  /// <remarks>
  /// 此方法不提供訪問存儲過程輸出參數和返回值
  /// 示例: 
  ///  int result = ExecuteNonQuery(conn, trans, "PublishOrders", 24, 36);
  /// </remarks>
  /// <param name="transaction">一個有效的數據庫鏈接對象</param>
  /// <param name="spName">存儲過程名</param>
  /// <param name="parameterValues">分配給存儲過程輸入參數的對象數組</param>
  /// <returns>返回受影響的行數</returns>
  public static int ExecuteNonQuery(SqlTransaction transaction, string spName, params object[] parameterValues)
  {
   if( transaction == null ) throw new ArgumentNullException( "transaction" );
   if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );
   if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

   // 若是有參數值
   if ((parameterValues != null) && (parameterValues.Length > 0))
   {
    // 從緩存中加載存儲過程參數,若是緩存中不存在則從數據庫中檢索參數信息並加載到緩存中. ()
    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

    // 給存儲過程參數賦值
    AssignParameterValues(commandParameters, parameterValues);

    // 調用重載方法
    return ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName, commandParameters);
   }
   else
   {
    // 沒有參數值
    return ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName);
   }
  }

  #endregion ExecuteNonQuery方法結束

  #region ExecuteDataset方法

  /// <summary>
  /// 執行指定數據庫鏈接字符串的命令,返回DataSet.
  /// </summary>
  /// <remarks>
  /// 示例: 
  ///  DataSet ds = ExecuteDataset(connString, CommandType.StoredProcedure, "GetOrders");
  /// </remarks>
  /// <param name="connectionString">一個有效的數據庫鏈接字符串</param>
  /// <param name="commandType">命令類型 (存儲過程,命令文本或其它)</param>
  /// <param name="commandText">存儲過程名稱或T-SQL語句</param>
  /// <returns>返回一個包含結果集的DataSet</returns>
  public static DataSet ExecuteDataset(string connectionString, CommandType commandType, string commandText)
  {
   return ExecuteDataset(connectionString, commandType, commandText, (SqlParameter[])null);
  }

  /// <summary>
  /// 執行指定數據庫鏈接字符串的命令,返回DataSet.
  /// </summary>
  /// <remarks>
  /// 示例:
  ///  DataSet ds = ExecuteDataset(connString, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
  /// </remarks>
  /// <param name="connectionString">一個有效的數據庫鏈接字符串</param>
  /// <param name="commandType">命令類型 (存儲過程,命令文本或其它)</param>
  /// <param name="commandText">存儲過程名稱或T-SQL語句</param>
  /// <param name="commandParameters">SqlParamters參數數組</param>
  /// <returns>返回一個包含結果集的DataSet</returns>
  public static DataSet ExecuteDataset(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
  {
   if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );

   // 建立並打開數據庫鏈接對象,操做完成釋放對象.
   using (SqlConnection connection = new SqlConnection(connectionString))
   {
    connection.Open();

    // 調用指定數據庫鏈接字符串重載方法.
    return ExecuteDataset(connection, commandType, commandText, commandParameters);
   }
  }

  /// <summary>
  /// 執行指定數據庫鏈接字符串的命令,直接提供參數值,返回DataSet.
  /// </summary>
  /// <remarks>
  /// 此方法不提供訪問存儲過程輸出參數和返回值.
  /// 示例:
  ///  DataSet ds = ExecuteDataset(connString, "GetOrders", 24, 36);
  /// </remarks>
  /// <param name="connectionString">一個有效的數據庫鏈接字符串</param>
  /// <param name="spName">存儲過程名</param>
  /// <param name="parameterValues">分配給存儲過程輸入參數的對象數組</param>
  /// <returns>返回一個包含結果集的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))
   {
    // 從緩存中檢索存儲過程參數
    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

    // 給存儲過程參數分配值
    AssignParameterValues(commandParameters, parameterValues);

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

  /// <summary>
  /// 執行指定數據庫鏈接對象的命令,返回DataSet.
  /// </summary>
  /// <remarks>
  /// 示例: 
  ///  DataSet ds = ExecuteDataset(conn, CommandType.StoredProcedure, "GetOrders");
  /// </remarks>
  /// <param name="connection">一個有效的數據庫鏈接對象</param>
  /// <param name="commandType">命令類型 (存儲過程,命令文本或其它)</param>
  /// <param name="commandText">存儲過程名或T-SQL語句</param>
  /// <returns>返回一個包含結果集的DataSet</returns>
  public static DataSet ExecuteDataset(SqlConnection connection, CommandType commandType, string commandText)
  {
   return ExecuteDataset(connection, commandType, commandText, (SqlParameter[])null);
  }
       
  /// <summary>
  /// 執行指定數據庫鏈接對象的命令,指定存儲過程參數,返回DataSet.
  /// </summary>
  /// <remarks>
  /// 示例: 
  ///  DataSet ds = ExecuteDataset(conn, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
  /// </remarks>
  /// <param name="connection">一個有效的數據庫鏈接對象</param>
  /// <param name="commandType">命令類型 (存儲過程,命令文本或其它)</param>
  /// <param name="commandText">存儲過程名或T-SQL語句</param>
  /// <param name="commandParameters">SqlParamter參數數組</param>
  /// <returns>返回一個包含結果集的DataSet</returns>
  public static DataSet ExecuteDataset(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
  {
   if( connection == null ) throw new ArgumentNullException( "connection" );

   // 預處理
   SqlCommand cmd = new SqlCommand();
   bool mustCloseConnection = false;
   PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection );
               
   // 建立SqlDataAdapter和DataSet.
   using( SqlDataAdapter da = new SqlDataAdapter(cmd) )
   {
    DataSet ds = new DataSet();

    // 填充DataSet.
    da.Fill(ds);
               
    cmd.Parameters.Clear();

    if( mustCloseConnection )
     connection.Close();

    return ds;
   }   
  }
       
  /// <summary>
  /// 執行指定數據庫鏈接對象的命令,指定參數值,返回DataSet.
  /// </summary>
  /// <remarks>
  /// 此方法不提供訪問存儲過程輸入參數和返回值.
  /// 示例.: 
  ///  DataSet ds = ExecuteDataset(conn, "GetOrders", 24, 36);
  /// </remarks>
  /// <param name="connection">一個有效的數據庫鏈接對象</param>
  /// <param name="spName">存儲過程名</param>
  /// <param name="parameterValues">分配給存儲過程輸入參數的對象數組</param>
  /// <returns>返回一個包含結果集的DataSet</returns>
  public static DataSet ExecuteDataset(SqlConnection connection, string spName, params object[] parameterValues)
  {
   if( connection == null ) throw new ArgumentNullException( "connection" );
   if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

   if ((parameterValues != null) && (parameterValues.Length > 0))
   {
    // 比緩存中加載存儲過程參數
    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

    // 給存儲過程參數分配值
    AssignParameterValues(commandParameters, parameterValues);

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

  /// <summary>
  /// 執行指定事務的命令,返回DataSet.
  /// </summary>
  /// <remarks>
  /// 示例: 
  ///  DataSet ds = ExecuteDataset(trans, CommandType.StoredProcedure, "GetOrders");
  /// </remarks>
  /// <param name="transaction">事務</param>
  /// <param name="commandType">命令類型 (存儲過程,命令文本或其它)</param>
  /// <param name="commandText">存儲過程名或T-SQL語句</param>
  /// <returns>返回一個包含結果集的DataSet</returns>
  public static DataSet ExecuteDataset(SqlTransaction transaction, CommandType commandType, string commandText)
  {
   return ExecuteDataset(transaction, commandType, commandText, (SqlParameter[])null);
  }
       
  /// <summary>
  /// 執行指定事務的命令,指定參數,返回DataSet.
  /// </summary>
  /// <remarks>
  /// 示例: 
  ///  DataSet ds = ExecuteDataset(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
  /// </remarks>
  /// <param name="transaction">事務</param>
  /// <param name="commandType">命令類型 (存儲過程,命令文本或其它)</param>
  /// <param name="commandText">存儲過程名或T-SQL語句</param>
  /// <param name="commandParameters">SqlParamter參數數組</param>
  /// <returns>返回一個包含結果集的DataSet</returns>
  public static DataSet ExecuteDataset(SqlTransaction transaction, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
  {
   if( transaction == null ) throw new ArgumentNullException( "transaction" );
   if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );

   // 預處理
   SqlCommand cmd = new SqlCommand();
   bool mustCloseConnection = false;
   PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection );
               
   // 建立 DataAdapter & DataSet
   using( SqlDataAdapter da = new SqlDataAdapter(cmd) )
   {
    DataSet ds = new DataSet();
    da.Fill(ds);
    cmd.Parameters.Clear();
    return ds;
   }   
  }
       
  /// <summary>
  /// 執行指定事務的命令,指定參數值,返回DataSet.
  /// </summary>
  /// <remarks>
  /// 此方法不提供訪問存儲過程輸入參數和返回值.
  /// 示例.: 
  ///  DataSet ds = ExecuteDataset(trans, "GetOrders", 24, 36);
  /// </remarks>
  /// <param name="transaction">事務</param>
  /// <param name="spName">存儲過程名</param>
  /// <param name="parameterValues">分配給存儲過程輸入參數的對象數組</param>
  /// <returns>返回一個包含結果集的DataSet</returns>
  public static DataSet ExecuteDataset(SqlTransaction transaction, string spName, params object[] parameterValues)
  {
   if( transaction == null ) throw new ArgumentNullException( "transaction" );
   if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );
   if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );
           
   if ((parameterValues != null) && (parameterValues.Length > 0))
   {
    // 從緩存中加載存儲過程參數
    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

    // 給存儲過程參數分配值
    AssignParameterValues(commandParameters, parameterValues);

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

  #endregion ExecuteDataset數據集命令結束
       
  #region ExecuteReader 數據閱讀器

  /// <summary>
  /// 枚舉,標識數據庫鏈接是由SqlHelper提供仍是由調用者提供
  /// </summary>
  private enum SqlConnectionOwnership   
  {
   /// <summary>由SqlHelper提供鏈接</summary>
   Internal,
   /// <summary>由調用者提供鏈接</summary>
   External
  }

  /// <summary>
  /// 執行指定數據庫鏈接對象的數據閱讀器.
  /// </summary>
  /// <remarks>
  /// 若是是SqlHelper打開鏈接,當鏈接關閉DataReader也將關閉.
  /// 若是是調用都打開鏈接,DataReader由調用都管理.
  /// </remarks>
  /// <param name="connection">一個有效的數據庫鏈接對象</param>
  /// <param name="transaction">一個有效的事務,或者爲 'null'</param>
  /// <param name="commandType">命令類型 (存儲過程,命令文本或其它)</param>
  /// <param name="commandText">存儲過程名或T-SQL語句</param>
  /// <param name="commandParameters">SqlParameters參數數組,若是沒有參數則爲'null'</param>
  /// <param name="connectionOwnership">標識數據庫鏈接對象是由調用者提供仍是由SqlHelper提供</param>
  /// <returns>返回包含結果集的SqlDataReader</returns>
  private static SqlDataReader ExecuteReader(SqlConnection connection, SqlTransaction transaction, CommandType commandType, string commandText, SqlParameter[] commandParameters, SqlConnectionOwnership connectionOwnership)
  {   
   if( connection == null ) throw new ArgumentNullException( "connection" );

   bool mustCloseConnection = false;
   // 建立命令
   SqlCommand cmd = new SqlCommand();
   try
   {
    PrepareCommand(cmd, connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection );
           
    // 建立數據閱讀器
    SqlDataReader dataReader;

    if (connectionOwnership == SqlConnectionOwnership.External)
    {
     dataReader = cmd.ExecuteReader();
    }
    else
    {
     dataReader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
    }
           
    // 清除參數,以便再次使用..
    // HACK: There is a problem here, the output parameter values are fletched
    // when the reader is closed, so if the parameters are detached from the command
    // then the SqlReader can磘 set its values.
    // When this happen, the parameters can磘 be used again in other command.
    bool canClear = true;
    foreach(SqlParameter commandParameter in cmd.Parameters)
    {
     if (commandParameter.Direction != ParameterDirection.Input)
      canClear = false;
    }
           
    if (canClear)
    {
     cmd.Parameters.Clear();
    }

    return dataReader;
   }
   catch
   {
    if( mustCloseConnection )
     connection.Close();
    throw;
   }
  }

  /// <summary>
  /// 執行指定數據庫鏈接字符串的數據閱讀器.
  /// </summary>
  /// <remarks>
  /// 示例: 
  ///  SqlDataReader dr = ExecuteReader(connString, CommandType.StoredProcedure, "GetOrders");
  /// </remarks>
  /// <param name="connectionString">一個有效的數據庫鏈接字符串</param>
  /// <param name="commandType">命令類型 (存儲過程,命令文本或其它)</param>
  /// <param name="commandText">存儲過程名或T-SQL語句</param>
  /// <returns>返回包含結果集的SqlDataReader</returns>
  public static SqlDataReader ExecuteReader(string connectionString, CommandType commandType, string commandText)
  {
   return ExecuteReader(connectionString, commandType, commandText, (SqlParameter[])null);
  }

  /// <summary>
  /// 執行指定數據庫鏈接字符串的數據閱讀器,指定參數.
  /// </summary>
  /// <remarks>
  /// 示例: 
  ///  SqlDataReader dr = ExecuteReader(connString, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
  /// </remarks>
  /// <param name="connectionString">一個有效的數據庫鏈接字符串</param>
  /// <param name="commandType">命令類型 (存儲過程,命令文本或其它)</param>
  /// <param name="commandText">存儲過程名或T-SQL語句</param>
  /// <param name="commandParameters">SqlParamter參數數組(new SqlParameter("@prodid", 24))</param>
  /// <returns>返回包含結果集的SqlDataReader</returns>
  public static SqlDataReader ExecuteReader(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
  {
   if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );
   SqlConnection connection = null;
   try
   {
    connection = new SqlConnection(connectionString);
    connection.Open();

    return ExecuteReader(connection, null, commandType, commandText, commandParameters,SqlConnectionOwnership.Internal);
   }
   catch
   {
    // If we fail to return the SqlDatReader, we need to close the connection ourselves
    if( connection != null ) connection.Close();
    throw;
   }
           
  }

  /// <summary>
  /// 執行指定數據庫鏈接字符串的數據閱讀器,指定參數值.
  /// </summary>
  /// <remarks>
  /// 此方法不提供訪問存儲過程輸出參數和返回值參數.
  /// 示例: 
  ///  SqlDataReader dr = ExecuteReader(connString, "GetOrders", 24, 36);
  /// </remarks>
  /// <param name="connectionString">一個有效的數據庫鏈接字符串</param>
  /// <param name="spName">存儲過程名</param>
  /// <param name="parameterValues">分配給存儲過程輸入參數的對象數組</param>
  /// <returns>返回包含結果集的SqlDataReader</returns>
  public static SqlDataReader ExecuteReader(string connectionString, string spName, params object[] parameterValues)
  {
   if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );
   if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );
           
   if ((parameterValues != null) && (parameterValues.Length > 0))
   {
    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

    AssignParameterValues(commandParameters, parameterValues);

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

  /// <summary>
  /// 執行指定數據庫鏈接對象的數據閱讀器.
  /// </summary>
  /// <remarks>
  /// 示例: 
  ///  SqlDataReader dr = ExecuteReader(conn, CommandType.StoredProcedure, "GetOrders");
  /// </remarks>
  /// <param name="connection">一個有效的數據庫鏈接對象</param>
  /// <param name="commandType">命令類型 (存儲過程,命令文本或其它)</param>
  /// <param name="commandText">存儲過程名或T-SQL語句</param>
  /// <returns>返回包含結果集的SqlDataReader</returns>
  public static SqlDataReader ExecuteReader(SqlConnection connection, CommandType commandType, string commandText)
  {
   return ExecuteReader(connection, commandType, commandText, (SqlParameter[])null);
  }

  /// <summary>
  /// [調用者方式]執行指定數據庫鏈接對象的數據閱讀器,指定參數.
  /// </summary>
  /// <remarks>
  /// 示例: 
  ///  SqlDataReader dr = ExecuteReader(conn, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
  /// </remarks>
  /// <param name="connection">一個有效的數據庫鏈接對象</param>
  /// <param name="commandType">命令類型 (存儲過程,命令文本或其它)</param>
  /// <param name="commandText">命令類型 (存儲過程,命令文本或其它)</param>
  /// <param name="commandParameters">SqlParamter參數數組</param>
  /// <returns>返回包含結果集的SqlDataReader</returns>
  public static SqlDataReader ExecuteReader(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
  {
   return ExecuteReader(connection, (SqlTransaction)null, commandType, commandText, commandParameters, SqlConnectionOwnership.External);
  }

  /// <summary>
  /// [調用者方式]執行指定數據庫鏈接對象的數據閱讀器,指定參數值.
  /// </summary>
  /// <remarks>
  /// 此方法不提供訪問存儲過程輸出參數和返回值參數.
  /// 示例: 
  ///  SqlDataReader dr = ExecuteReader(conn, "GetOrders", 24, 36);
  /// </remarks>
  /// <param name="connection">一個有效的數據庫鏈接對象</param>
  /// <param name="spName">T存儲過程名</param>
  /// <param name="parameterValues">分配給存儲過程輸入參數的對象數組</param>
  /// <returns>返回包含結果集的SqlDataReader</returns>
  public static SqlDataReader ExecuteReader(SqlConnection connection, string spName, params object[] parameterValues)
  {
   if( connection == null ) throw new ArgumentNullException( "connection" );
   if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

   if ((parameterValues != null) && (parameterValues.Length > 0))
   {
    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

    AssignParameterValues(commandParameters, parameterValues);

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

  /// <summary>
  /// [調用者方式]執行指定數據庫事務的數據閱讀器,指定參數值.
  /// </summary>
  /// <remarks>
  /// 示例: 
  ///  SqlDataReader dr = ExecuteReader(trans, CommandType.StoredProcedure, "GetOrders");
  /// </remarks>
  /// <param name="transaction">一個有效的鏈接事務</param>
  /// <param name="commandType">命令類型 (存儲過程,命令文本或其它)</param>
  /// <param name="commandText">存儲過程名稱或T-SQL語句</param>
  /// <returns>返回包含結果集的SqlDataReader</returns>
  public static SqlDataReader ExecuteReader(SqlTransaction transaction, CommandType commandType, string commandText)
  {
   return ExecuteReader(transaction, commandType, commandText, (SqlParameter[])null);
  }

  /// <summary>
  /// [調用者方式]執行指定數據庫事務的數據閱讀器,指定參數.
  /// </summary>
  /// <remarks>
  /// 示例: 
  ///   SqlDataReader dr = ExecuteReader(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
  /// </remarks>
  /// <param name="transaction">一個有效的鏈接事務</param>
  /// <param name="commandType">命令類型 (存儲過程,命令文本或其它)</param>
  /// <param name="commandText">存儲過程名稱或T-SQL語句</param>
  /// <param name="commandParameters">分配給命令的SqlParamter參數數組</param>
  /// <returns>返回包含結果集的SqlDataReader</returns>
  public static SqlDataReader ExecuteReader(SqlTransaction transaction, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
  {
   if( transaction == null ) throw new ArgumentNullException( "transaction" );
   if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );

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

  /// <summary>
  /// [調用者方式]執行指定數據庫事務的數據閱讀器,指定參數值.
  /// </summary>
  /// <remarks>
  /// 此方法不提供訪問存儲過程輸出參數和返回值參數.
  ///
  /// 示例: 
  ///  SqlDataReader dr = ExecuteReader(trans, "GetOrders", 24, 36);
  /// </remarks>
  /// <param name="transaction">一個有效的鏈接事務</param>
  /// <param name="spName">存儲過程名稱</param>
  /// <param name="parameterValues">分配給存儲過程輸入參數的對象數組</param>
  /// <returns>返回包含結果集的SqlDataReader</returns>
  public static SqlDataReader ExecuteReader(SqlTransaction transaction, string spName, params object[] parameterValues)
  {
   if( transaction == null ) throw new ArgumentNullException( "transaction" );
   if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );
   if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

   // 若是有參數值
   if ((parameterValues != null) && (parameterValues.Length > 0))
   {
    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

    AssignParameterValues(commandParameters, parameterValues);

    return ExecuteReader(transaction, CommandType.StoredProcedure, spName, commandParameters);
   }
   else
   {
    // 沒有參數值
    return ExecuteReader(transaction, CommandType.StoredProcedure, spName);
   }
  }

  #endregion ExecuteReader數據閱讀器

  #region ExecuteScalar 返回結果集中的第一行第一列
       
  /// <summary>
  /// 執行指定數據庫鏈接字符串的命令,返回結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">一個有效的數據庫鏈接字符串</param>
  /// <param name="commandType">命令類型 (存儲過程,命令文本或其它)</param>
  /// <param name="commandText">存儲過程名稱或T-SQL語句</param>
  /// <returns>返回結果集中的第一行第一列</returns>
  public static object ExecuteScalar(string connectionString, CommandType commandType, string commandText)
  {
   // 執行參數爲空的方法
   return ExecuteScalar(connectionString, commandType, commandText, (SqlParameter[])null);
  }

  /// <summary>
  /// 執行指定數據庫鏈接字符串的命令,指定參數,返回結果集中的第一行第一列.
  /// </summary>
  /// <remarks>
  /// 示例: 
  ///  int orderCount = (int)ExecuteScalar(connString, CommandType.StoredProcedure, "GetOrderCount", new SqlParameter("@prodid", 24));
  /// </remarks>
  /// <param name="connectionString">一個有效的數據庫鏈接字符串</param>
  /// <param name="commandType">命令類型 (存儲過程,命令文本或其它)</param>
  /// <param name="commandText">存儲過程名稱或T-SQL語句</param>
  /// <param name="commandParameters">分配給命令的SqlParamter參數數組</param>
  /// <returns>返回結果集中的第一行第一列</returns>
  public static object ExecuteScalar(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
  {
   if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );
   // 建立並打開數據庫鏈接對象,操做完成釋放對象.
   using (SqlConnection connection = new SqlConnection(connectionString))
   {
    connection.Open();

    // 調用指定數據庫鏈接字符串重載方法.
    return ExecuteScalar(connection, commandType, commandText, commandParameters);
   }
  }

  /// <summary>
  /// 執行指定數據庫鏈接字符串的命令,指定參數值,返回結果集中的第一行第一列.
  /// </summary>
  /// <remarks>
  /// 此方法不提供訪問存儲過程輸出參數和返回值參數.
  ///
  /// 示例: 
  ///  int orderCount = (int)ExecuteScalar(connString, "GetOrderCount", 24, 36);
  /// </remarks>
  /// <param name="connectionString">一個有效的數據庫鏈接字符串</param>
  /// <param name="spName">存儲過程名稱</param>
  /// <param name="parameterValues">分配給存儲過程輸入參數的對象數組</param>
  /// <returns>返回結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" );
           
   // 若是有參數值
   if ((parameterValues != null) && (parameterValues.Length > 0))
   {
    // 從緩存中加載存儲過程參數,若是緩存中不存在則從數據庫中檢索參數信息並加載到緩存中. ()
    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

    // 給存儲過程參數賦值
    AssignParameterValues(commandParameters, parameterValues);

    // 調用重載方法
    return ExecuteScalar(connectionString, CommandType.StoredProcedure, spName, commandParameters);
   }
   else
   {
    // 沒有參數值
    return ExecuteScalar(connectionString, CommandType.StoredProcedure, spName);
   }
  }

  /// <summary>
  /// 執行指定數據庫鏈接對象的命令,返回結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">一個有效的數據庫鏈接對象</param>
  /// <param name="commandType">命令類型 (存儲過程,命令文本或其它)</param>
  /// <param name="commandText">存儲過程名稱或T-SQL語句</param>
  /// <returns>返回結果集中的第一行第一列</returns>
  public static object ExecuteScalar(SqlConnection connection, CommandType commandType, string commandText)
  {
   // 執行參數爲空的方法
   return ExecuteScalar(connection, commandType, commandText, (SqlParameter[])null);
  }

  /// <summary>
  /// 執行指定數據庫鏈接對象的命令,指定參數,返回結果集中的第一行第一列.
  /// </summary>
  /// <remarks>
  /// 示例: 
  ///  int orderCount = (int)ExecuteScalar(conn, CommandType.StoredProcedure, "GetOrderCount", new SqlParameter("@prodid", 24));
  /// </remarks>
  /// <param name="connection">一個有效的數據庫鏈接對象</param>
  /// <param name="commandType">命令類型 (存儲過程,命令文本或其它)</param>
  /// <param name="commandText">存儲過程名稱或T-SQL語句</param>
  /// <param name="commandParameters">分配給命令的SqlParamter參數數組</param>
  /// <returns>返回結果集中的第一行第一列</returns>
  public static object ExecuteScalar(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
  {
   if( connection == null ) throw new ArgumentNullException( "connection" );

   // 建立SqlCommand命令,並進行預處理
   SqlCommand cmd = new SqlCommand();

   bool mustCloseConnection = false;
   PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection );
               
   // 執行SqlCommand命令,並返回結果.
   object retval = cmd.ExecuteScalar();
               
   // 清除參數,以便再次使用.
   cmd.Parameters.Clear();

   if( mustCloseConnection )
    connection.Close();

   return retval;
  }

  /// <summary>
  /// 執行指定數據庫鏈接對象的命令,指定參數值,返回結果集中的第一行第一列.
  /// </summary>
  /// <remarks>
  /// 此方法不提供訪問存儲過程輸出參數和返回值參數.
  ///
  /// 示例: 
  ///  int orderCount = (int)ExecuteScalar(conn, "GetOrderCount", 24, 36);
  /// </remarks>
  /// <param name="connection">一個有效的數據庫鏈接對象</param>
  /// <param name="spName">存儲過程名稱</param>
  /// <param name="parameterValues">分配給存儲過程輸入參數的對象數組</param>
  /// <returns>返回結果集中的第一行第一列</returns>
  public static object ExecuteScalar(SqlConnection connection, string spName, params object[] parameterValues)
  {
   if( connection == null ) throw new ArgumentNullException( "connection" );
   if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

   // 若是有參數值
   if ((parameterValues != null) && (parameterValues.Length > 0))
   {
    // 從緩存中加載存儲過程參數,若是緩存中不存在則從數據庫中檢索參數信息並加載到緩存中. ()
    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

    // 給存儲過程參數賦值
    AssignParameterValues(commandParameters, parameterValues);

    // 調用重載方法
    return ExecuteScalar(connection, CommandType.StoredProcedure, spName, commandParameters);
   }
   else
   {
    // 沒有參數值
    return ExecuteScalar(connection, CommandType.StoredProcedure, spName);
   }
  }

  /// <summary>
  /// 執行指定數據庫事務的命令,返回結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">一個有效的鏈接事務</param>
  /// <param name="commandType">命令類型 (存儲過程,命令文本或其它)</param>
  /// <param name="commandText">存儲過程名稱或T-SQL語句</param>
  /// <returns>返回結果集中的第一行第一列</returns>
  public static object ExecuteScalar(SqlTransaction transaction, CommandType commandType, string commandText)
  {
   // 執行參數爲空的方法
   return ExecuteScalar(transaction, commandType, commandText, (SqlParameter[])null);
  }

  /// <summary>
  /// 執行指定數據庫事務的命令,指定參數,返回結果集中的第一行第一列.
  /// </summary>
  /// <remarks>
  /// 示例: 
  ///  int orderCount = (int)ExecuteScalar(trans, CommandType.StoredProcedure, "GetOrderCount", new SqlParameter("@prodid", 24));
  /// </remarks>
  /// <param name="transaction">一個有效的鏈接事務</param>
  /// <param name="commandType">命令類型 (存儲過程,命令文本或其它)</param>
  /// <param name="commandText">存儲過程名稱或T-SQL語句</param>
  /// <param name="commandParameters">分配給命令的SqlParamter參數數組</param>
  /// <returns>返回結果集中的第一行第一列</returns>
  public static object ExecuteScalar(SqlTransaction transaction, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
  {
   if( transaction == null ) throw new ArgumentNullException( "transaction" );
   if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );

   // 建立SqlCommand命令,並進行預處理
   SqlCommand cmd = new SqlCommand();
   bool mustCloseConnection = false;
   PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection );
               
   // 執行SqlCommand命令,並返回結果.
   object retval = cmd.ExecuteScalar();
               
   // 清除參數,以便再次使用.
   cmd.Parameters.Clear();
   return retval;
  }

  /// <summary>
  /// 執行指定數據庫事務的命令,指定參數值,返回結果集中的第一行第一列.
  /// </summary>
  /// <remarks>
  /// 此方法不提供訪問存儲過程輸出參數和返回值參數.
  ///
  /// 示例: 
  ///  int orderCount = (int)ExecuteScalar(trans, "GetOrderCount", 24, 36);
  /// </remarks>
  /// <param name="transaction">一個有效的鏈接事務</param>
  /// <param name="spName">存儲過程名稱</param>
  /// <param name="parameterValues">分配給存儲過程輸入參數的對象數組</param>
  /// <returns>返回結果集中的第一行第一列</returns>
  public static object ExecuteScalar(SqlTransaction transaction, string spName, params object[] parameterValues)
  {
   if( transaction == null ) throw new ArgumentNullException( "transaction" );
   if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );
   if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

   // 若是有參數值
   if ((parameterValues != null) && (parameterValues.Length > 0))
   {
    // PPull the parameters for this stored procedure from the parameter cache ()
    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

    // 給存儲過程參數賦值
    AssignParameterValues(commandParameters, parameterValues);

    // 調用重載方法
    return ExecuteScalar(transaction, CommandType.StoredProcedure, spName, commandParameters);
   }
   else
   {
    // 沒有參數值
    return ExecuteScalar(transaction, CommandType.StoredProcedure, spName);
   }
  }

  #endregion ExecuteScalar   

  #region ExecuteXmlReader XML閱讀器
  /// <summary>
  /// 執行指定數據庫鏈接對象的SqlCommand命令,併產生一個XmlReader對象作爲結果集返回.
  /// </summary>
  /// <remarks>
  /// 示例: 
  ///  XmlReader r = ExecuteXmlReader(conn, CommandType.StoredProcedure, "GetOrders");
  /// </remarks>
  /// <param name="connection">一個有效的數據庫鏈接對象</param>
  /// <param name="commandType">命令類型 (存儲過程,命令文本或其它)</param>
  /// <param name="commandText">存儲過程名稱或T-SQL語句 using "FOR XML AUTO"</param>
  /// <returns>返回XmlReader結果集對象.</returns>
  public static XmlReader ExecuteXmlReader(SqlConnection connection, CommandType commandType, string commandText)
  {
   // 執行參數爲空的方法
   return ExecuteXmlReader(connection, commandType, commandText, (SqlParameter[])null);
  }

  /// <summary>
  /// 執行指定數據庫鏈接對象的SqlCommand命令,併產生一個XmlReader對象作爲結果集返回,指定參數.
  /// </summary>
  /// <remarks>
  /// 示例: 
  ///  XmlReader r = ExecuteXmlReader(conn, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
  /// </remarks>
  /// <param name="connection">一個有效的數據庫鏈接對象</param>
  /// <param name="commandType">命令類型 (存儲過程,命令文本或其它)</param>
  /// <param name="commandText">存儲過程名稱或T-SQL語句 using "FOR XML AUTO"</param>
  /// <param name="commandParameters">分配給命令的SqlParamter參數數組</param>
  /// <returns>返回XmlReader結果集對象.</returns>
  public static XmlReader ExecuteXmlReader(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
  {
   if( connection == null ) throw new ArgumentNullException( "connection" );

   bool mustCloseConnection = false;
   // 建立SqlCommand命令,並進行預處理
   SqlCommand cmd = new SqlCommand();
   try
   {
    PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection );
           
    // 執行命令
    XmlReader retval = cmd.ExecuteXmlReader();
           
    // 清除參數,以便再次使用.
    cmd.Parameters.Clear();

    return retval;
   }
   catch
   {   
    if( mustCloseConnection )
     connection.Close();
    throw;
   }
  }

  /// <summary>
  /// 執行指定數據庫鏈接對象的SqlCommand命令,併產生一個XmlReader對象作爲結果集返回,指定參數值.
  /// </summary>
  /// <remarks>
  /// 此方法不提供訪問存儲過程輸出參數和返回值參數.
  ///
  /// 示例: 
  ///  XmlReader r = ExecuteXmlReader(conn, "GetOrders", 24, 36);
  /// </remarks>
  /// <param name="connection">一個有效的數據庫鏈接對象</param>
  /// <param name="spName">存儲過程名稱 using "FOR XML AUTO"</param>
  /// <param name="parameterValues">分配給存儲過程輸入參數的對象數組</param>
  /// <returns>返回XmlReader結果集對象.</returns>
  public static XmlReader ExecuteXmlReader(SqlConnection connection, string spName, params object[] parameterValues)
  {
   if( connection == null ) throw new ArgumentNullException( "connection" );
   if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

   // 若是有參數值
   if ((parameterValues != null) && (parameterValues.Length > 0))
   {
    // 從緩存中加載存儲過程參數,若是緩存中不存在則從數據庫中檢索參數信息並加載到緩存中. ()
    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

    // 給存儲過程參數賦值
    AssignParameterValues(commandParameters, parameterValues);

    // 調用重載方法
    return ExecuteXmlReader(connection, CommandType.StoredProcedure, spName, commandParameters);
   }
   else
   {
    // 沒有參數值
    return ExecuteXmlReader(connection, CommandType.StoredProcedure, spName);
   }
  }

  /// <summary>
  /// 執行指定數據庫事務的SqlCommand命令,併產生一個XmlReader對象作爲結果集返回.
  /// </summary>
  /// <remarks>
  /// 示例: 
  ///  XmlReader r = ExecuteXmlReader(trans, CommandType.StoredProcedure, "GetOrders");
  /// </remarks>
  /// <param name="transaction">一個有效的鏈接事務</param>
  /// <param name="commandType">命令類型 (存儲過程,命令文本或其它)</param>
  /// <param name="commandText">存儲過程名稱或T-SQL語句 using "FOR XML AUTO"</param>
  /// <returns>返回XmlReader結果集對象.</returns>
  public static XmlReader ExecuteXmlReader(SqlTransaction transaction, CommandType commandType, string commandText)
  {
   // 執行參數爲空的方法
   return ExecuteXmlReader(transaction, commandType, commandText, (SqlParameter[])null);
  }

  /// <summary>
  /// 執行指定數據庫事務的SqlCommand命令,併產生一個XmlReader對象作爲結果集返回,指定參數.
  /// </summary>
  /// <remarks>
  /// 示例: 
  ///  XmlReader r = ExecuteXmlReader(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
  /// </remarks>
  /// <param name="transaction">一個有效的鏈接事務</param>
  /// <param name="commandType">命令類型 (存儲過程,命令文本或其它)</param>
  /// <param name="commandText">存儲過程名稱或T-SQL語句 using "FOR XML AUTO"</param>
  /// <param name="commandParameters">分配給命令的SqlParamter參數數組</param>
  /// <returns>返回XmlReader結果集對象.</returns>
  public static XmlReader ExecuteXmlReader(SqlTransaction transaction, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
  {
   if( transaction == null ) throw new ArgumentNullException( "transaction" );
   if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );

   // 建立SqlCommand命令,並進行預處理
   SqlCommand cmd = new SqlCommand();
   bool mustCloseConnection = false;
   PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection );
           
   // 執行命令
   XmlReader retval = cmd.ExecuteXmlReader();
           
   // 清除參數,以便再次使用.
   cmd.Parameters.Clear();
   return retval;           
  }

  /// <summary>
  /// 執行指定數據庫事務的SqlCommand命令,併產生一個XmlReader對象作爲結果集返回,指定參數值.
  /// </summary>
  /// <remarks>
  /// 此方法不提供訪問存儲過程輸出參數和返回值參數.
  ///
  /// 示例: 
  ///  XmlReader r = ExecuteXmlReader(trans, "GetOrders", 24, 36);
  /// </remarks>
  /// <param name="transaction">一個有效的鏈接事務</param>
  /// <param name="spName">存儲過程名稱</param>
  /// <param name="parameterValues">分配給存儲過程輸入參數的對象數組</param>
  /// <returns>返回一個包含結果集的DataSet.</returns>
  public static XmlReader ExecuteXmlReader(SqlTransaction transaction, string spName, params object[] parameterValues)
  {
   if( transaction == null ) throw new ArgumentNullException( "transaction" );
   if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );
   if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

   // 若是有參數值
   if ((parameterValues != null) && (parameterValues.Length > 0))
   {
    // 從緩存中加載存儲過程參數,若是緩存中不存在則從數據庫中檢索參數信息並加載到緩存中. ()
    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

    // 給存儲過程參數賦值
    AssignParameterValues(commandParameters, parameterValues);

    // 調用重載方法
    return ExecuteXmlReader(transaction, CommandType.StoredProcedure, spName, commandParameters);
   }
   else
   {
    // 沒有參數值
    return ExecuteXmlReader(transaction, CommandType.StoredProcedure, spName);
   }
  }

  #endregion ExecuteXmlReader 閱讀器結束

  #region FillDataset 填充數據集
  /// <summary>
  /// 執行指定數據庫鏈接字符串的命令,映射數據表並填充數據集.
  /// </summary>
  /// <remarks>
  /// 示例: 
  ///  FillDataset(connString, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"});
  /// </remarks>
  /// <param name="connectionString">一個有效的數據庫鏈接字符串</param>
  /// <param name="commandType">命令類型 (存儲過程,命令文本或其它)</param>
  /// <param name="commandText">存儲過程名稱或T-SQL語句</param>
  /// <param name="dataSet">要填充結果集的DataSet實例</param>
  /// <param name="tableNames">表映射的數據表數組
  /// 用戶定義的表名 (可有是實際的表名.)</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" );
           
   // 建立並打開數據庫鏈接對象,操做完成釋放對象.
   using (SqlConnection connection = new SqlConnection(connectionString))
   {
    connection.Open();

    // 調用指定數據庫鏈接字符串重載方法.
    FillDataset(connection, commandType, commandText, dataSet, tableNames);
   }
  }

  /// <summary>
  /// 執行指定數據庫鏈接字符串的命令,映射數據表並填充數據集.指定命令參數.
  /// </summary>
  /// <remarks>
  /// 示例: 
  ///  FillDataset(connString, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, new SqlParameter("@prodid", 24));
  /// </remarks>
  /// <param name="connectionString">一個有效的數據庫鏈接字符串</param>
  /// <param name="commandType">命令類型 (存儲過程,命令文本或其它)</param>
  /// <param name="commandText">存儲過程名稱或T-SQL語句</param>
  /// <param name="commandParameters">分配給命令的SqlParamter參數數組</param>
  /// <param name="dataSet">要填充結果集的DataSet實例</param>
  /// <param name="tableNames">表映射的數據表數組
  /// 用戶定義的表名 (可有是實際的表名.)
  /// </param>
  public static void FillDataset(string connectionString, CommandType commandType,
   string commandText, DataSet dataSet, string[] tableNames,
   params SqlParameter[] commandParameters)
  {
   if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );
   if( dataSet == null ) throw new ArgumentNullException( "dataSet" );
   // 建立並打開數據庫鏈接對象,操做完成釋放對象.
   using (SqlConnection connection = new SqlConnection(connectionString))
   {
    connection.Open();

    // 調用指定數據庫鏈接字符串重載方法.
    FillDataset(connection, commandType, commandText, dataSet, tableNames, commandParameters);
   }
  }

  /// <summary>
  /// 執行指定數據庫鏈接字符串的命令,映射數據表並填充數據集,指定存儲過程參數值.
  /// </summary>
  /// <remarks>
  /// 此方法不提供訪問存儲過程輸出參數和返回值參數.
  ///
  /// 示例: 
  ///  FillDataset(connString, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, 24);
  /// </remarks>
  /// <param name="connectionString">一個有效的數據庫鏈接字符串</param>
  /// <param name="spName">存儲過程名稱</param>
  /// <param name="dataSet">要填充結果集的DataSet實例</param>
  /// <param name="tableNames">表映射的數據表數組
  /// 用戶定義的表名 (可有是實際的表名.)
  /// </param>   
  /// <param name="parameterValues">分配給存儲過程輸入參數的對象數組</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" );
   // 建立並打開數據庫鏈接對象,操做完成釋放對象.
   using (SqlConnection connection = new SqlConnection(connectionString))
   {
    connection.Open();

    // 調用指定數據庫鏈接字符串重載方法.
    FillDataset (connection, spName, dataSet, tableNames, parameterValues);
   }
  }

  /// <summary>
  /// 執行指定數據庫鏈接對象的命令,映射數據表並填充數據集.
  /// </summary>
  /// <remarks>
  /// 示例: 
  ///  FillDataset(conn, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"});
  /// </remarks>
  /// <param name="connection">一個有效的數據庫鏈接對象</param>
  /// <param name="commandType">命令類型 (存儲過程,命令文本或其它)</param>
  /// <param name="commandText">存儲過程名稱或T-SQL語句</param>
  /// <param name="dataSet">要填充結果集的DataSet實例</param>
  /// <param name="tableNames">表映射的數據表數組
  /// 用戶定義的表名 (可有是實際的表名.)
  /// </param>   
  public static void FillDataset(SqlConnection connection, CommandType commandType,
   string commandText, DataSet dataSet, string[] tableNames)
  {
   FillDataset(connection, commandType, commandText, dataSet, tableNames, null);
  }

  /// <summary>
  /// 執行指定數據庫鏈接對象的命令,映射數據表並填充數據集,指定參數.
  /// </summary>
  /// <remarks>
  /// 示例: 
  ///  FillDataset(conn, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, new SqlParameter("@prodid", 24));
  /// </remarks>
  /// <param name="connection">一個有效的數據庫鏈接對象</param>
  /// <param name="commandType">命令類型 (存儲過程,命令文本或其它)</param>
  /// <param name="commandText">存儲過程名稱或T-SQL語句</param>
  /// <param name="dataSet">要填充結果集的DataSet實例</param>
  /// <param name="tableNames">表映射的數據表數組
  /// 用戶定義的表名 (可有是實際的表名.)
  /// </param>
  /// <param name="commandParameters">分配給命令的SqlParamter參數數組</param>
  public static void FillDataset(SqlConnection connection, CommandType commandType,
   string commandText, DataSet dataSet, string[] tableNames,
   params SqlParameter[] commandParameters)
  {
   FillDataset(connection, null, commandType, commandText, dataSet, tableNames, commandParameters);
  }

  /// <summary>
  /// 執行指定數據庫鏈接對象的命令,映射數據表並填充數據集,指定存儲過程參數值.
  /// </summary>
  /// <remarks>
  /// 此方法不提供訪問存儲過程輸出參數和返回值參數.
  ///
  /// 示例: 
  ///  FillDataset(conn, "GetOrders", ds, new string[] {"orders"}, 24, 36);
  /// </remarks>
  /// <param name="connection">一個有效的數據庫鏈接對象</param>
  /// <param name="spName">存儲過程名稱</param>
  /// <param name="dataSet">要填充結果集的DataSet實例</param>
  /// <param name="tableNames">表映射的數據表數組
  /// 用戶定義的表名 (可有是實際的表名.)
  /// </param>
  /// <param name="parameterValues">分配給存儲過程輸入參數的對象數組</param>
  public static void FillDataset(SqlConnection connection, string spName,
   DataSet dataSet, string[] tableNames,
   params object[] parameterValues)
  {
   if ( connection == null ) throw new ArgumentNullException( "connection" );
   if (dataSet == null ) throw new ArgumentNullException( "dataSet" );
   if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

   // 若是有參數值
   if ((parameterValues != null) && (parameterValues.Length > 0))
   {
    // 從緩存中加載存儲過程參數,若是緩存中不存在則從數據庫中檢索參數信息並加載到緩存中. ()
    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

    // 給存儲過程參數賦值
    AssignParameterValues(commandParameters, parameterValues);

    // 調用重載方法
    FillDataset(connection, CommandType.StoredProcedure, spName, dataSet, tableNames, commandParameters);
   }
   else
   {
    // 沒有參數值
    FillDataset(connection, CommandType.StoredProcedure, spName, dataSet, tableNames);
   }   
  }

  /// <summary>
  /// 執行指定數據庫事務的命令,映射數據表並填充數據集.
  /// </summary>
  /// <remarks>
  /// 示例: 
  ///  FillDataset(trans, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"});
  /// </remarks>
  /// <param name="transaction">一個有效的鏈接事務</param>
  /// <param name="commandType">命令類型 (存儲過程,命令文本或其它)</param>
  /// <param name="commandText">存儲過程名稱或T-SQL語句</param>
  /// <param name="dataSet">要填充結果集的DataSet實例</param>
  /// <param name="tableNames">表映射的數據表數組
  /// 用戶定義的表名 (可有是實際的表名.)
  /// </param>
  public static void FillDataset(SqlTransaction transaction, CommandType commandType,
   string commandText,
   DataSet dataSet, string[] tableNames)
  {
   FillDataset (transaction, commandType, commandText, dataSet, tableNames, null);   
  }

  /// <summary>
  /// 執行指定數據庫事務的命令,映射數據表並填充數據集,指定參數.
  /// </summary>
  /// <remarks>
  /// 示例: 
  ///  FillDataset(trans, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, new SqlParameter("@prodid", 24));
  /// </remarks>
  /// <param name="transaction">一個有效的鏈接事務</param>
  /// <param name="commandType">命令類型 (存儲過程,命令文本或其它)</param>
  /// <param name="commandText">存儲過程名稱或T-SQL語句</param>
  /// <param name="dataSet">要填充結果集的DataSet實例</param>
  /// <param name="tableNames">表映射的數據表數組
  /// 用戶定義的表名 (可有是實際的表名.)
  /// </param>
  /// <param name="commandParameters">分配給命令的SqlParamter參數數組</param>
  public static void FillDataset(SqlTransaction transaction, CommandType commandType,
   string commandText, DataSet dataSet, string[] tableNames,
   params SqlParameter[] commandParameters)
  {
   FillDataset(transaction.Connection, transaction, commandType, commandText, dataSet, tableNames, commandParameters);
  }

  /// <summary>
  /// 執行指定數據庫事務的命令,映射數據表並填充數據集,指定存儲過程參數值.
  /// </summary>
  /// <remarks>
  /// 此方法不提供訪問存儲過程輸出參數和返回值參數.
  ///
  /// 示例: 
  ///  FillDataset(trans, "GetOrders", ds, new string[]{"orders"}, 24, 36);
  /// </remarks>
  /// <param name="transaction">一個有效的鏈接事務</param>
  /// <param name="spName">存儲過程名稱</param>
  /// <param name="dataSet">要填充結果集的DataSet實例</param>
  /// <param name="tableNames">表映射的數據表數組
  /// 用戶定義的表名 (可有是實際的表名.)
  /// </param>
  /// <param name="parameterValues">分配給存儲過程輸入參數的對象數組</param>
  public static void FillDataset(SqlTransaction transaction, string spName,
   DataSet dataSet, string[] tableNames,
   params object[] parameterValues)
  {
   if( transaction == null ) throw new ArgumentNullException( "transaction" );
   if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );
   if( dataSet == null ) throw new ArgumentNullException( "dataSet" );
   if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

   // 若是有參數值
   if ((parameterValues != null) && (parameterValues.Length > 0))
   {
    // 從緩存中加載存儲過程參數,若是緩存中不存在則從數據庫中檢索參數信息並加載到緩存中. ()
    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

    // 給存儲過程參數賦值
    AssignParameterValues(commandParameters, parameterValues);

    // 調用重載方法
    FillDataset(transaction, CommandType.StoredProcedure, spName, dataSet, tableNames, commandParameters);
   }
   else
   {
    // 沒有參數值
    FillDataset(transaction, CommandType.StoredProcedure, spName, dataSet, tableNames);
   }   
  }

  /// <summary>
  /// [私有方法][內部調用]執行指定數據庫鏈接對象/事務的命令,映射數據表並填充數據集,DataSet/TableNames/SqlParameters.
  /// </summary>
  /// <remarks>
  /// 示例: 
  ///  FillDataset(conn, trans, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, new SqlParameter("@prodid", 24));
  /// </remarks>
  /// <param name="connection">一個有效的數據庫鏈接對象</param>
  /// <param name="transaction">一個有效的鏈接事務</param>
  /// <param name="commandType">命令類型 (存儲過程,命令文本或其它)</param>
  /// <param name="commandText">存儲過程名稱或T-SQL語句</param>
  /// <param name="dataSet">要填充結果集的DataSet實例</param>
  /// <param name="tableNames">表映射的數據表數組
  /// 用戶定義的表名 (可有是實際的表名.)
  /// </param>
  /// <param name="commandParameters">分配給命令的SqlParamter參數數組</param>
  private static void FillDataset(SqlConnection connection, SqlTransaction transaction, CommandType commandType,
   string commandText, DataSet dataSet, string[] tableNames,
   params SqlParameter[] commandParameters)
  {
   if( connection == null ) throw new ArgumentNullException( "connection" );
   if( dataSet == null ) throw new ArgumentNullException( "dataSet" );

   // 建立SqlCommand命令,並進行預處理
   SqlCommand command = new SqlCommand();
   bool mustCloseConnection = false;
   PrepareCommand(command, connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection );
               
   // 執行命令
   using( SqlDataAdapter dataAdapter = new SqlDataAdapter(command) )
   {
               
    // 追加表映射
    if (tableNames != null && tableNames.Length > 0)
    {
     string tableName = "Table";
     for (int index=0; index < tableNames.Length; index++)
     {
      if( tableNames[index] == null || tableNames[index].Length == 0 ) throw new ArgumentException( "The tableNames parameter must contain a list of tables, a value was provided as null or empty string.", "tableNames" );
      dataAdapter.TableMappings.Add(tableName, tableNames[index]);
      tableName += (index + 1).ToString();
     }
    }
               
    // 填充數據集使用默認表名稱
    dataAdapter.Fill(dataSet);

    // 清除參數,以便再次使用.
    command.Parameters.Clear();
   }

   if( mustCloseConnection )
    connection.Close();
  }
  #endregion
       
  #region UpdateDataset 更新數據集
  /// <summary>
  /// 執行數據集更新到數據庫,指定inserted, updated, or deleted命令.
  /// </summary>
  /// <remarks>
  /// 示例: 
  ///  UpdateDataset(conn, insertCommand, deleteCommand, updateCommand, dataSet, "Order");
  /// </remarks>
  /// <param name="insertCommand">[追加記錄]一個有效的T-SQL語句或存儲過程</param>
  /// <param name="deleteCommand">[刪除記錄]一個有效的T-SQL語句或存儲過程</param>
  /// <param name="updateCommand">[更新記錄]一個有效的T-SQL語句或存儲過程</param>
  /// <param name="dataSet">要更新到數據庫的DataSet</param>
  /// <param name="tableName">要更新到數據庫的DataTable</param>
  public static void UpdateDataset(SqlCommand insertCommand, SqlCommand deleteCommand, SqlCommand updateCommand, DataSet dataSet, string tableName)
  {
   if( insertCommand == null ) throw new ArgumentNullException( "insertCommand" );
   if( deleteCommand == null ) throw new ArgumentNullException( "deleteCommand" );
   if( updateCommand == null ) throw new ArgumentNullException( "updateCommand" );
   if( tableName == null || tableName.Length == 0 ) throw new ArgumentNullException( "tableName" );

   // 建立SqlDataAdapter,當操做完成後釋放.
   using (SqlDataAdapter dataAdapter = new SqlDataAdapter())
   {
    // 設置數據適配器命令
    dataAdapter.UpdateCommand = updateCommand;
    dataAdapter.InsertCommand = insertCommand;
    dataAdapter.DeleteCommand = deleteCommand;

    // 更新數據集改變到數據庫
    dataAdapter.Update (dataSet, tableName);

    // 提交全部改變到數據集.
    dataSet.AcceptChanges();
   }
  }
  #endregion

  #region CreateCommand 建立一條SqlCommand命令
  /// <summary>
  /// 建立SqlCommand命令,指定數據庫鏈接對象,存儲過程名和參數.
  /// </summary>
  /// <remarks>
  /// 示例: 
  ///  SqlCommand command = CreateCommand(conn, "AddCustomer", "CustomerID", "CustomerName");
  /// </remarks>
  /// <param name="connection">一個有效的數據庫鏈接對象</param>
  /// <param name="spName">存儲過程名稱</param>
  /// <param name="sourceColumns">源表的列名稱數組</param>
  /// <returns>返回SqlCommand命令</returns>
  public static SqlCommand CreateCommand(SqlConnection connection, string spName, params string[] sourceColumns)
  {
   if( connection == null ) throw new ArgumentNullException( "connection" );
   if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

   // 建立命令
   SqlCommand cmd = new SqlCommand( spName, connection );
   cmd.CommandType = CommandType.StoredProcedure;

   // 若是有參數值
   if ((sourceColumns != null) && (sourceColumns.Length > 0))
   {
    // 從緩存中加載存儲過程參數,若是緩存中不存在則從數據庫中檢索參數信息並加載到緩存中. ()
    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

    // 將源表的列到映射到DataSet命令中.
    for (int index=0; index < sourceColumns.Length; index++)
     commandParameters[index].SourceColumn = sourceColumns[index];

    // Attach the discovered parameters to the SqlCommand object
    AttachParameters (cmd, commandParameters);
   }

   return cmd;
  }
  #endregion

  #region ExecuteNonQueryTypedParams 類型化參數(DataRow)
  /// <summary>
  /// 執行指定鏈接數據庫鏈接字符串的存儲過程,使用DataRow作爲參數值,返回受影響的行數.
  /// </summary>
  /// <param name="connectionString">一個有效的數據庫鏈接字符串</param>
  /// <param name="spName">存儲過程名稱</param>
  /// <param name="dataRow">使用DataRow做爲參數值</param>
  /// <returns>返回影響的行數</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" );
           
   // 若是row有值,存儲過程必須初始化.
   if (dataRow != null && dataRow.ItemArray.Length > 0)
   {
    // 從緩存中加載存儲過程參數,若是緩存中不存在則從數據庫中檢索參數信息並加載到緩存中. ()
    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);
               
    // 分配參數值
    AssignParameterValues(commandParameters, dataRow);
                               
    return SqlHelper.ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName, commandParameters);
   }
   else
   {
    return SqlHelper.ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName);
   }
  }

  /// <summary>
  /// 執行指定鏈接數據庫鏈接對象的存儲過程,使用DataRow作爲參數值,返回受影響的行數.
  /// </summary>
  /// <param name="connection">一個有效的數據庫鏈接對象</param>
  /// <param name="spName">存儲過程名稱</param>
  /// <param name="dataRow">使用DataRow做爲參數值</param>
  /// <returns>返回影響的行數</returns>
  public static int ExecuteNonQueryTypedParams(SqlConnection connection, String spName, DataRow dataRow)
  {
   if( connection == null ) throw new ArgumentNullException( "connection" );
   if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

   // 若是row有值,存儲過程必須初始化.
   if (dataRow != null && dataRow.ItemArray.Length > 0)
   {
    // 從緩存中加載存儲過程參數,若是緩存中不存在則從數據庫中檢索參數信息並加載到緩存中. ()
    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);
               
    // 分配參數值
    AssignParameterValues(commandParameters, dataRow);
                               
    return SqlHelper.ExecuteNonQuery(connection, CommandType.StoredProcedure, spName, commandParameters);
   }
   else
   {
    return SqlHelper.ExecuteNonQuery(connection, CommandType.StoredProcedure, spName);
   }
  }

  /// <summary>
  /// 執行指定鏈接數據庫事物的存儲過程,使用DataRow作爲參數值,返回受影響的行數.
  /// </summary>
  /// <param name="transaction">一個有效的鏈接事務 object</param>
  /// <param name="spName">存儲過程名稱</param>
  /// <param name="dataRow">使用DataRow做爲參數值</param>
  /// <returns>返回影響的行數</returns>
  public static int ExecuteNonQueryTypedParams(SqlTransaction transaction, String spName, DataRow dataRow)
  {
   if( transaction == null ) throw new ArgumentNullException( "transaction" );
   if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );
   if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

   // Sf the row has values, the store procedure parameters must be initialized
   if (dataRow != null && dataRow.ItemArray.Length > 0)
   {
    // 從緩存中加載存儲過程參數,若是緩存中不存在則從數據庫中檢索參數信息並加載到緩存中. ()
    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);
               
    // 分配參數值
    AssignParameterValues(commandParameters, dataRow);
                               
    return SqlHelper.ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName, commandParameters);
   }
   else
   {
    return SqlHelper.ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName);
   }
  }
  #endregion

  #region ExecuteDatasetTypedParams 類型化參數(DataRow)
  /// <summary>
  /// 執行指定鏈接數據庫鏈接字符串的存儲過程,使用DataRow作爲參數值,返回DataSet.
  /// </summary>
  /// <param name="connectionString">一個有效的數據庫鏈接字符串</param>
  /// <param name="spName">存儲過程名稱</param>
  /// <param name="dataRow">使用DataRow做爲參數值</param>
  /// <returns>返回一個包含結果集的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" );

   //若是row有值,存儲過程必須初始化.
   if ( dataRow != null && dataRow.ItemArray.Length > 0)
   {
    // 從緩存中加載存儲過程參數,若是緩存中不存在則從數據庫中檢索參數信息並加載到緩存中. ()
    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);
               
    // 分配參數值
    AssignParameterValues(commandParameters, dataRow);
               
    return SqlHelper.ExecuteDataset(connectionString, CommandType.StoredProcedure, spName, commandParameters);
   }
   else
   {
    return SqlHelper.ExecuteDataset(connectionString, CommandType.StoredProcedure, spName);
   }
  }

  /// <summary>
  /// 執行指定鏈接數據庫鏈接對象的存儲過程,使用DataRow作爲參數值,返回DataSet.
  /// </summary>
  /// <param name="connection">一個有效的數據庫鏈接對象</param>
  /// <param name="spName">存儲過程名稱</param>
  /// <param name="dataRow">使用DataRow做爲參數值</param>
  /// <returns>返回一個包含結果集的DataSet.</returns>
  ///
  public static DataSet ExecuteDatasetTypedParams(SqlConnection connection, String spName, DataRow dataRow)
  {
   if( connection == null ) throw new ArgumentNullException( "connection" );
   if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

   // 若是row有值,存儲過程必須初始化.
   if( dataRow != null && dataRow.ItemArray.Length > 0)
   {
    // 從緩存中加載存儲過程參數,若是緩存中不存在則從數據庫中檢索參數信息並加載到緩存中. ()
    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);
               
    // 分配參數值
    AssignParameterValues(commandParameters, dataRow);
               
    return SqlHelper.ExecuteDataset(connection, CommandType.StoredProcedure, spName, commandParameters);
   }
   else
   {
    return SqlHelper.ExecuteDataset(connection, CommandType.StoredProcedure, spName);
   }
  }

  /// <summary>
  /// 執行指定鏈接數據庫事務的存儲過程,使用DataRow作爲參數值,返回DataSet.
  /// </summary>
  /// <param name="transaction">一個有效的鏈接事務 object</param>
  /// <param name="spName">存儲過程名稱</param>
  /// <param name="dataRow">使用DataRow做爲參數值</param>
  /// <returns>返回一個包含結果集的DataSet.</returns>
  public static DataSet ExecuteDatasetTypedParams(SqlTransaction transaction, String spName, DataRow dataRow)
  {
   if( transaction == null ) throw new ArgumentNullException( "transaction" );
   if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );
   if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

   // 若是row有值,存儲過程必須初始化.
   if( dataRow != null && dataRow.ItemArray.Length > 0)
   {
    // 從緩存中加載存儲過程參數,若是緩存中不存在則從數據庫中檢索參數信息並加載到緩存中. ()
    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);
               
    // 分配參數值
    AssignParameterValues(commandParameters, dataRow);
               
    return SqlHelper.ExecuteDataset(transaction, CommandType.StoredProcedure, spName, commandParameters);
   }
   else
   {
    return SqlHelper.ExecuteDataset(transaction, CommandType.StoredProcedure, spName);
   }
  }

  #endregion

  #region ExecuteReaderTypedParams 類型化參數(DataRow)
  /// <summary>
  /// 執行指定鏈接數據庫鏈接字符串的存儲過程,使用DataRow作爲參數值,返回DataReader.
  /// </summary>
  /// <param name="connectionString">一個有效的數據庫鏈接字符串</param>
  /// <param name="spName">存儲過程名稱</param>
  /// <param name="dataRow">使用DataRow做爲參數值</param>
  /// <returns>返回包含結果集的SqlDataReader</returns>
  public static SqlDataReader ExecuteReaderTypedParams(String connectionString, String spName, DataRow dataRow)
  {
   if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );
   if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );
           
   // 若是row有值,存儲過程必須初始化.
   if ( dataRow != null && dataRow.ItemArray.Length > 0 )
   {
    // 從緩存中加載存儲過程參數,若是緩存中不存在則從數據庫中檢索參數信息並加載到緩存中. ()
    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);
               
    // 分配參數值
    AssignParameterValues(commandParameters, dataRow);
               
    return SqlHelper.ExecuteReader(connectionString, CommandType.StoredProcedure, spName, commandParameters);
   }
   else
   {
    return SqlHelper.ExecuteReader(connectionString, CommandType.StoredProcedure, spName);
   }
  }

               
  /// <summary>
  /// 執行指定鏈接數據庫鏈接對象的存儲過程,使用DataRow作爲參數值,返回DataReader.
  /// </summary>
  /// <param name="connection">一個有效的數據庫鏈接對象</param>
  /// <param name="spName">存儲過程名稱</param>
  /// <param name="dataRow">使用DataRow做爲參數值</param>
  /// <returns>返回包含結果集的SqlDataReader</returns>
  public static SqlDataReader ExecuteReaderTypedParams(SqlConnection connection, String spName, DataRow dataRow)
  {
   if( connection == null ) throw new ArgumentNullException( "connection" );
   if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

   // 若是row有值,存儲過程必須初始化.
   if( dataRow != null && dataRow.ItemArray.Length > 0)
   {
    // 從緩存中加載存儲過程參數,若是緩存中不存在則從數據庫中檢索參數信息並加載到緩存中. ()
    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);
               
    // 分配參數值
    AssignParameterValues(commandParameters, dataRow);
               
    return SqlHelper.ExecuteReader(connection, CommandType.StoredProcedure, spName, commandParameters);
   }
   else
   {
    return SqlHelper.ExecuteReader(connection, CommandType.StoredProcedure, spName);
   }
  }
       
  /// <summary>
  /// 執行指定鏈接數據庫事物的存儲過程,使用DataRow作爲參數值,返回DataReader.
  /// </summary>
  /// <param name="transaction">一個有效的鏈接事務 object</param>
  /// <param name="spName">存儲過程名稱</param>
  /// <param name="dataRow">使用DataRow做爲參數值</param>
  /// <returns>返回包含結果集的SqlDataReader</returns>
  public static SqlDataReader ExecuteReaderTypedParams(SqlTransaction transaction, String spName, DataRow dataRow)
  {
   if( transaction == null ) throw new ArgumentNullException( "transaction" );
   if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );
   if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

   // 若是row有值,存儲過程必須初始化.
   if( dataRow != null && dataRow.ItemArray.Length > 0 )
   {
    // 從緩存中加載存儲過程參數,若是緩存中不存在則從數據庫中檢索參數信息並加載到緩存中. ()
    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);
               
    // 分配參數值
    AssignParameterValues(commandParameters, dataRow);
               
    return SqlHelper.ExecuteReader(transaction, CommandType.StoredProcedure, spName, commandParameters);
   }
   else
   {
    return SqlHelper.ExecuteReader(transaction, CommandType.StoredProcedure, spName);
   }
  }
  #endregion

  #region ExecuteScalarTypedParams 類型化參數(DataRow)
  /// <summary>
  /// 執行指定鏈接數據庫鏈接字符串的存儲過程,使用DataRow作爲參數值,返回結果集中的第一行第一列.
  /// </summary>
  /// <param name="connectionString">一個有效的數據庫鏈接字符串</param>
  /// <param name="spName">存儲過程名稱</param>
  /// <param name="dataRow">使用DataRow做爲參數值</param>
  /// <returns>返回結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" );
           
   // 若是row有值,存儲過程必須初始化.
   if( dataRow != null && dataRow.ItemArray.Length > 0)
   {
    // 從緩存中加載存儲過程參數,若是緩存中不存在則從數據庫中檢索參數信息並加載到緩存中. ()
    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);
               
    // 分配參數值
    AssignParameterValues(commandParameters, dataRow);
               
    return SqlHelper.ExecuteScalar(connectionString, CommandType.StoredProcedure, spName, commandParameters);
   }
   else
   {
    return SqlHelper.ExecuteScalar(connectionString, CommandType.StoredProcedure, spName);
   }
  }

  /// <summary>
  /// 執行指定鏈接數據庫鏈接對象的存儲過程,使用DataRow作爲參數值,返回結果集中的第一行第一列.
  /// </summary>
  /// <param name="connection">一個有效的數據庫鏈接對象</param>
  /// <param name="spName">存儲過程名稱</param>
  /// <param name="dataRow">使用DataRow做爲參數值</param>
  /// <returns>返回結果集中的第一行第一列</returns>
  public static object ExecuteScalarTypedParams(SqlConnection connection, String spName, DataRow dataRow)
  {
   if( connection == null ) throw new ArgumentNullException( "connection" );
   if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

   // 若是row有值,存儲過程必須初始化.
   if( dataRow != null && dataRow.ItemArray.Length > 0)
   {
    // 從緩存中加載存儲過程參數,若是緩存中不存在則從數據庫中檢索參數信息並加載到緩存中. ()
    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);
               
    // 分配參數值
    AssignParameterValues(commandParameters, dataRow);
               
    return SqlHelper.ExecuteScalar(connection, CommandType.StoredProcedure, spName, commandParameters);
   }
   else
   {
    return SqlHelper.ExecuteScalar(connection, CommandType.StoredProcedure, spName);
   }
  }

  /// <summary>
  /// 執行指定鏈接數據庫事務的存儲過程,使用DataRow作爲參數值,返回結果集中的第一行第一列.
  /// </summary>
  /// <param name="transaction">一個有效的鏈接事務 object</param>
  /// <param name="spName">存儲過程名稱</param>
  /// <param name="dataRow">使用DataRow做爲參數值</param>
  /// <returns>返回結果集中的第一行第一列</returns>
  public static object ExecuteScalarTypedParams(SqlTransaction transaction, String spName, DataRow dataRow)
  {
   if( transaction == null ) throw new ArgumentNullException( "transaction" );
   if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );
   if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

   // 若是row有值,存儲過程必須初始化.
   if( dataRow != null && dataRow.ItemArray.Length > 0)
   {
    // 從緩存中加載存儲過程參數,若是緩存中不存在則從數據庫中檢索參數信息並加載到緩存中. ()
    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);
               
    // 分配參數值
    AssignParameterValues(commandParameters, dataRow);
               
    return SqlHelper.ExecuteScalar(transaction, CommandType.StoredProcedure, spName, commandParameters);
   }
   else
   {
    return SqlHelper.ExecuteScalar(transaction, CommandType.StoredProcedure, spName);
   }
  }
  #endregion

  #region ExecuteXmlReaderTypedParams 類型化參數(DataRow)
  /// <summary>
  /// 執行指定鏈接數據庫鏈接對象的存儲過程,使用DataRow作爲參數值,返回XmlReader類型的結果集.
  /// </summary>
  /// <param name="connection">一個有效的數據庫鏈接對象</param>
  /// <param name="spName">存儲過程名稱</param>
  /// <param name="dataRow">使用DataRow做爲參數值</param>
  /// <returns>返回XmlReader結果集對象.</returns>
  public static XmlReader ExecuteXmlReaderTypedParams(SqlConnection connection, String spName, DataRow dataRow)
  {
   if( connection == null ) throw new ArgumentNullException( "connection" );
   if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

   // 若是row有值,存儲過程必須初始化.
   if( dataRow != null && dataRow.ItemArray.Length > 0)
   {
    // 從緩存中加載存儲過程參數,若是緩存中不存在則從數據庫中檢索參數信息並加載到緩存中. ()
    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);
               
    // 分配參數值
    AssignParameterValues(commandParameters, dataRow);
               
    return SqlHelper.ExecuteXmlReader(connection, CommandType.StoredProcedure, spName, commandParameters);
   }
   else
   {
    return SqlHelper.ExecuteXmlReader(connection, CommandType.StoredProcedure, spName);
   }
  }

  /// <summary>
  /// 執行指定鏈接數據庫事務的存儲過程,使用DataRow作爲參數值,返回XmlReader類型的結果集.
  /// </summary>
  /// <param name="transaction">一個有效的鏈接事務 object</param>
  /// <param name="spName">存儲過程名稱</param>
  /// <param name="dataRow">使用DataRow做爲參數值</param>
  /// <returns>返回XmlReader結果集對象.</returns>
  public static XmlReader ExecuteXmlReaderTypedParams(SqlTransaction transaction, String spName, DataRow dataRow)
  {
   if( transaction == null ) throw new ArgumentNullException( "transaction" );
   if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );
   if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

   // 若是row有值,存儲過程必須初始化.
   if( dataRow != null && dataRow.ItemArray.Length > 0)
   {
    // 從緩存中加載存儲過程參數,若是緩存中不存在則從數據庫中檢索參數信息並加載到緩存中. ()
    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);
               
    // 分配參數值
    AssignParameterValues(commandParameters, dataRow);
               
    return SqlHelper.ExecuteXmlReader(transaction, CommandType.StoredProcedure, spName, commandParameters);
   }
   else
   {
    return SqlHelper.ExecuteXmlReader(transaction, CommandType.StoredProcedure, spName);
   }
  }
  #endregion

 }
//////////////////////////////////////////////////////////////////////////////////能夠放入另外一個類SqlHelperParameterCache
 /// <summary>
 /// SqlHelperParameterCache提供緩存存儲過程參數,並可以在運行時從存儲過程當中探索參數.
 /// </summary>
 public sealed class SqlHelperParameterCache
 {
  #region 私有方法,字段,構造函數
  // 私有構造函數,妨止類被實例化.
  private SqlHelperParameterCache() {}

  // 這個方法要注意
  private static Hashtable paramCache = Hashtable.Synchronized(new Hashtable());

  /// <summary>
  /// 探索運行時的存儲過程,返回SqlParameter參數數組.
  /// 初始化參數值爲 DBNull.Value.
  /// </summary>
  /// <param name="connection">一個有效的數據庫鏈接</param>
  /// <param name="spName">存儲過程名稱</param>
  /// <param name="includeReturnValueParameter">是否包含返回值參數</param>
  /// <returns>返回SqlParameter參數數組</returns>
  private static SqlParameter[] DiscoverSpParameterSet(SqlConnection connection, string spName, bool includeReturnValueParameter)
  {
   if( connection == null ) throw new ArgumentNullException( "connection" );
   if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

   SqlCommand cmd = new SqlCommand(spName, connection);
   cmd.CommandType = CommandType.StoredProcedure;

   connection.Open();
   // 檢索cmd指定的存儲過程的參數信息,並填充到cmd的Parameters參數集中.
   SqlCommandBuilder.DeriveParameters(cmd);
   connection.Close();
   // 若是不包含返回值參數,將參數集中的每個參數刪除.
   if (!includeReturnValueParameter)
   {
    cmd.Parameters.RemoveAt(0);
   }
               
   // 建立參數數組
   SqlParameter[] discoveredParameters = new SqlParameter[cmd.Parameters.Count];
   // 將cmd的Parameters參數集複製到discoveredParameters數組.
   cmd.Parameters.CopyTo(discoveredParameters, 0);

   // 初始化參數值爲 DBNull.Value.
   foreach (SqlParameter discoveredParameter in discoveredParameters)
   {
    discoveredParameter.Value = DBNull.Value;
   }
   return discoveredParameters;
  }

  /// <summary>
  /// SqlParameter參數數組的深層拷貝.
  /// </summary>
  /// <param name="originalParameters">原始參數數組</param>
  /// <returns>返回一個一樣的參數數組</returns>
  private static SqlParameter[] CloneParameters(SqlParameter[] originalParameters)
  {
   SqlParameter[] clonedParameters = new SqlParameter[originalParameters.Length];

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

   return clonedParameters;
  }

  #endregion 私有方法,字段,構造函數結束

  #region 緩存方法

  /// <summary>
  /// 追加參數數組到緩存.
  /// </summary>
  /// <param name="connectionString">一個有效的數據庫鏈接字符串</param>
  /// <param name="commandText">存儲過程名或SQL語句</param>
  /// <param name="commandParameters">要緩存的參數數組</param>
  public static void CacheParameterSet(string connectionString, string commandText, params SqlParameter[] commandParameters)
  {
   if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );
   if( commandText == null || commandText.Length == 0 ) throw new ArgumentNullException( "commandText" );

   string hashKey = connectionString + ":" + commandText;

   paramCache[hashKey] = commandParameters;
  }

  /// <summary>
  /// 從緩存中獲取參數數組.
  /// </summary>
  /// <param name="connectionString">一個有效的數據庫鏈接字符</param>
  /// <param name="commandText">存儲過程名或SQL語句</param>
  /// <returns>參數數組</returns>
  public static SqlParameter[] GetCachedParameterSet(string connectionString, string commandText)
  {
   if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );
   if( commandText == null || commandText.Length == 0 ) throw new ArgumentNullException( "commandText" );

   string hashKey = connectionString + ":" + commandText;

   SqlParameter[] cachedParameters = paramCache[hashKey] as SqlParameter[];
   if (cachedParameters == null)
   {           
    return null;
   }
   else
   {
    return CloneParameters(cachedParameters);
   }
  }

  #endregion 緩存方法結束

  #region 檢索指定的存儲過程的參數集

  /// <summary>
  /// 返回指定的存儲過程的參數集
  /// </summary>
  /// <remarks>
  /// 這個方法將查詢數據庫,並將信息存儲到緩存.
  /// </remarks>
  /// <param name="connectionString">一個有效的數據庫鏈接字符</param>
  /// <param name="spName">存儲過程名</param>
  /// <returns>返回SqlParameter參數數組</returns>
  public static SqlParameter[] GetSpParameterSet(string connectionString, string spName)
  {
   return GetSpParameterSet(connectionString, spName, false);
  }

  /// <summary>
  /// 返回指定的存儲過程的參數集
  /// </summary>
  /// <remarks>
  /// 這個方法將查詢數據庫,並將信息存儲到緩存.
  /// </remarks>
  /// <param name="connectionString">一個有效的數據庫鏈接字符.</param>
  /// <param name="spName">存儲過程名</param>
  /// <param name="includeReturnValueParameter">是否包含返回值參數</param>
  /// <returns>返回SqlParameter參數數組</returns>
  public static SqlParameter[] GetSpParameterSet(string connectionString, string spName, bool includeReturnValueParameter)
  {
   if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );
   if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

   using(SqlConnection connection = new SqlConnection(connectionString))
   {
    return GetSpParameterSetInternal(connection, spName, includeReturnValueParameter);
   }
  }

  /// <summary>
  /// [內部]返回指定的存儲過程的參數集(使用鏈接對象).
  /// </summary>
  /// <remarks>
  /// 這個方法將查詢數據庫,並將信息存儲到緩存.
  /// </remarks>
  /// <param name="connection">一個有效的數據庫鏈接字符</param>
  /// <param name="spName">存儲過程名</param>
  /// <returns>返回SqlParameter參數數組</returns>
  internal static SqlParameter[] GetSpParameterSet(SqlConnection connection, string spName)
  {
   return GetSpParameterSet(connection, spName, false);
  }

  /// <summary>
  /// [內部]返回指定的存儲過程的參數集(使用鏈接對象)
  /// </summary>
  /// <remarks>
  /// 這個方法將查詢數據庫,並將信息存儲到緩存.
  /// </remarks>
  /// <param name="connection">一個有效的數據庫鏈接對象</param>
  /// <param name="spName">存儲過程名</param>
  /// <param name="includeReturnValueParameter">
  /// 是否包含返回值參數
  /// </param>
  /// <returns>返回SqlParameter參數數組</returns>
  internal static SqlParameter[] GetSpParameterSet(SqlConnection connection, string spName, bool includeReturnValueParameter)
  {
   if( connection == null ) throw new ArgumentNullException( "connection" );
   using (SqlConnection clonedConnection = (SqlConnection)((ICloneable)connection).Clone())
   {
    return GetSpParameterSetInternal(clonedConnection, spName, includeReturnValueParameter);
   }
  }

  /// <summary>
  /// [私有]返回指定的存儲過程的參數集(使用鏈接對象)
  /// </summary>
  /// <param name="connection">一個有效的數據庫鏈接對象</param>
  /// <param name="spName">存儲過程名</param>
  /// <param name="includeReturnValueParameter">是否包含返回值參數</param>
  /// <returns>返回SqlParameter參數數組</returns>
  private static SqlParameter[] GetSpParameterSetInternal(SqlConnection connection, string spName, bool includeReturnValueParameter)
  {
   if( connection == null ) throw new ArgumentNullException( "connection" );
   if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

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

   SqlParameter[] cachedParameters;
           
   cachedParameters = paramCache[hashKey] as SqlParameter[];
   if (cachedParameters == null)
   {   
    SqlParameter[] spParameters = DiscoverSpParameterSet(connection, spName, includeReturnValueParameter);
    paramCache[hashKey] = spParameters;
    cachedParameters = spParameters;
   }
           
   return CloneParameters(cachedParameters);
  }
       
  #endregion 參數集檢索結束

 }
}

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