为什么MySQLDataAdapter.Fill（）第一次需要这么长时间。 [英] Why does MySQLDataAdapter.Fill() takes so long for the first time.

问题描述

在下面的代码中，如果我在不重新启动应用程序的情况下调用方法，da.Fill（ds）第一次占用大约500ms，第二次占用50ms。我试过DataReader同样的事情发生了。另一方面，我使用LINQ to SQL（在MS SQL Server上），这是第一次在大约50ms内返回记录。

Hi, In the code below da.Fill(ds) takes around 500ms for the first and drops to 50ms for the second if I call the method without restarting the application. I tried DataReader same thing happens with it. On the other hand I used LINQ to SQL (On MS SQL Server) which returned the records in around 50ms for the first time.

public List<GetEmployeeRightsResult> GetEmployeeRights(System.Nullable<int> p_EmployeeID)
       {
           try
           {


               List<GetEmployeeRightsResult> records = new List<GetEmployeeRightsResult>();

               if (Connection.State != ConnectionState.Open)
               {
                   Connection.Open();
               }

               Command = new MySqlCommand("GetEmployeeRights", Connection);
               Command.CommandType = CommandType.StoredProcedure;

               //Add Parameters is procedures requires.
               Command.Parameters.Add(new MySqlParameter("p_EmployeeID", p_EmployeeID));


               if (Transaction != null)
               {
                   Command.Transaction = Transaction;
               }

               da = new MySqlDataAdapter();
               da.SelectCommand = Command;

               ds = new DataSet();

               Stopwatch sw = new Stopwatch();
               sw.Start();
               da.Fill(ds);
               sw.Stop();
               //Writing Execution Time in label
               string ExecutionTimeTaken = string.Format("Minutes :{0}\nSeconds :{1}\n Mili seconds :{2}", sw.Elapsed.Minutes, sw.Elapsed.Seconds, sw.Elapsed.TotalMilliseconds);



               foreach (DataRow Row in ds.Tables[0].Rows)
               {
                   GetEmployeeRightsResult result = new GetEmployeeRightsResult()
                   {
                       FormID = Convert.ToInt32(Row["FormID"]),
                       FormName = Row["FormName"] == DBNull.Value ? null : (string)Row["FormName"],
                       CanAccess = Convert.ToBoolean(Row["CanAccess"]),
                       Type = Row["Type"] == DBNull.Value ? null : (string)Row["Type"],

                   };

                   records.Add(result);
               }


               return records;
           }
           catch
           {
               throw;
           }
       }

只有70行记录。

Just 70 lines of record.

BEGIN

IF(p_EmployeeID = 0)
THEN
	SELECT FormID,FormName,CanAccess,Type from RightsCatalog; 
ELSE
	SELECT
		 ER.StoreID
		,ER.FormID
		,FormName
		,IFNULL(ER.CanAccess,1) as CanAccess
		,RC.Type 
		FROM EmployeeRight ER 
		RIGHT OUTER JOIN RightsCatalog RC 
		ON RC.FormID = ER.FormID  
		WHERE EmployeeID = p_EmployeeID;
END IF;
-- ****** [Objec...  ts ] Script Date: 02/24/2014 10:00:33 *******

END

推荐答案

这可能是任何事情。 IDE错误，操作系统问题，即虚拟机或SSMS设置。

请参阅：

http://stackoverflow.com/questions/7992560/sqldataadapter-fill-suddenly-taking-a-long-time [ ^ ]

http://stackoverflow.com/questions/250713/sqldataadapter-fill-method-slow [ ^ ]



-KR

This could be anything. IDE bug, OS problem i.e Virtual Machine or settings of SSMS.
See this :
http://stackoverflow.com/questions/7992560/sqldataadapter-fill-suddenly-taking-a-long-time[^]
http://stackoverflow.com/questions/250713/sqldataadapter-fill-method-slow[^]

-KR

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