尝试Catch不能解决sql连接错误 [英] Try Catch not working on sql connection error

问题描述

请帮助我，我试图在sql server连接失败时捕获错误。



这是一个例子

Hi,

Please help me, I am trying to catch the error when the connection fails in sql server.

Here's the example

SqlConnection sqlConnectLocal;
DataTable dt = new DataTable();
string strConString = string.Empty;

dt = new DataTable();

try
{
sqlConnectLocal = webConnectServer(strConString);

SqlCommand cmd = new SqlCommand(strQuery, sqlConnectLocal);
SqlDataAdapter sqlda = new SqlDataAdapter(cmd);
sqlda.SelectCommand.CommandTimeout = 30;
sqlda.Fill(dt);
}
catch (SqlException ex)
{
}

现在，它应该输入catch语句，因为我故意使我的连接字符串错误，因为我想测试我的程序是否可以捕获sql连接错误。



但它停止处理而没有任何反应。没有错误显示它只是停止



我怎么能发现这个错误。



谢谢

Now, it should enter the catch statement because I intentionally made my connection string wrong because I want to test if my program can catch the sql connection error.

But instead it stop processing and nothing happen. No error showed it just stop

How can I catch this error.

Thank you

推荐答案

引用：

没有错误显示它只是停止

No error showed it just stop

当然它没有显示错误：你的 catch 块是空的！因为您的代码引发了 SqlException ，所以执行 catch 块中的代码。但是 catch 块中没有代码！

试试这个：

Of course it doesn't show an error: your catch block is empty! Because your code raised a SqlException, the code into your catch block gets executed. But there's no code in the catch block!
Try this:

catch (SqlException ex)
{
     Response.Write(String.Format("SqlException: {0}",ex.Message));
}
catch (Exception ex)
{
     Response.Write(String.Format("Exception: {0}", ex.Message));
}
finally
{
     if (sqlConnectLocal != null)
     {
        sqlConnectLocal.Close();
     }
}

我还关闭了 finally 块中的连接，因为它是重要的是连接关闭。







还要加第二个 catch 阻止，因为如果异常不是 SqlException ，它会自动跳转到 finally catch（Exception ex）{...} 块，则c $ c>阻止。



希望这有帮助。

I also closed the connection in a finally block, because it's important that the connection gets closed.



Also add a second catch block, because if the exception isn't a SqlException, it jumps automatically to the finally block if you don't add a catch (Exception ex) { ... } block.

Hope this helps.

这篇关于尝试Catch不能解决sql连接错误的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！