执行超时已过期。操作完成前超时时间已过或服务器未响应

Question

当我运行我的代码时，我得到以下异常：

An unhandled exception of type 'System.Data.SqlClient.SqlException' occurred in System.Data.dll

Additional information: Execution Timeout Expired. The timeout period elapsed prior to completion of the operation or the server is not responding.

我的代码如下：

    private void FillInDataGrid(string SQLstring)
    {
        string cn = ConfigurationManager.ConnectionStrings["Scratchpad"].ConnectionString; //hier wordt de databasestring opgehaald
        SqlConnection myConnection = new SqlConnection(cn);
        SqlDataAdapter dataadapter = new SqlDataAdapter(SQLstring, myConnection);
        DataSet ds = new DataSet();
        myConnection.Open();
        dataadapter.Fill(ds, "Authors_table");
        myConnection.Close();
        dataGridView1.DataSource = ds;
        dataGridView1.DataMember = "Authors_table";
    }

我的 SQLstring 如下：

SELECT dbo.[new].[colom1],dbo.[new].[colom2],dbo.[new].[colom3],dbo.[new].[colom4],  
                dbo.[new].[Value] as 'nieuwe Value',
                dbo.[old].[Value] as 'oude Value'
                FROM dbo.[new]
                JOIN dbo.[old] ON dbo.[new].[colom1] = dbo.[old].[colom1] and dbo.[new].[colom2] = dbo.[old].[colom2] and dbo.[new].[colom3] = dbo.[old].[colom3] and dbo.[new].[colom4] = dbo.[old].[colom4] 
                where dbo.[new].[Value] <> dbo.[old].[Value]

Answer 1

如果您的查询需要超过默认的 30 秒，您可能需要将 CommandTimeout 设置得更高。为此，您需要在该实例的 SelectCommand 属性上实例化 DataAdapter 后更改它，如下所示：

private void FillInDataGrid(string SQLstring)
{
    string cn = ConfigurationManager.ConnectionStrings["Scratchpad"].ConnectionString; //hier wordt de databasestring opgehaald
    DataSet ds = new DataSet();
    // dispose objects that implement IDisposable
    using(SqlConnection myConnection = new SqlConnection(cn))
    {
        SqlDataAdapter dataadapter = new SqlDataAdapter(SQLstring, myConnection);

        // set the CommandTimeout
        dataadapter.SelectCommand.CommandTimeout = 60;  // seconds

        myConnection.Open();
        dataadapter.Fill(ds, "Authors_table"); 
    }
    dataGridView1.DataSource = ds;
    dataGridView1.DataMember = "Authors_table";
}

另一个选项是解决您的查询。在Sql服务器中你可以分析execution plan。我敢打赌里面有一个完整的 table 扫描。您可以尝试在 [old] 和 [new] table 中的一个或两个列上添加索引。请记住，添加索引是以插入和更新的执行时间更长以及 space 要求为代价的。

执行超时已过期。操作完成前超时时间已过或服务器未响应

Execution Timeout Expired. The timeout period elapsed prior to completion of the operation or the server is not responding

c#

sql

sqldataadapter