Stored procedure times out when ran from code, but not from query tool

Question

I am trying to figure out why a stored procedure call takes seconds in a SQL server express query window, but when I run call the stored procedure in code the query TIMES OUT. We are using sql server 2008. I know it is hard to say exactly what is going on without seeing the stored procedure. I'm just hoping this is a known issue. Any guidance is much appreciated.

SQL query that calls "STORED_PROCEDURE_X" and runs in 2 seconds in SQL server express query window:

EXEC STORED_PROCEDURE_X '07/01/2010', '07/31/2010', 0, '', 'true','', 'Top 20'

Code that calls "STORED_PROCEDURE_X" and TIMES OUT:

SqlConnection connSQL = null;
SqlCommand sqlCmd = null;
SqlDataAdapter sqlDataAdpater = null;
DataTable returnData = null;

try
{
    returnData = new DataTable();
    connSQL = new SqlConnection(sqlConnection);
    sqlCmd = new SqlCommand("STORED_PROC_X", connSQL);
    if (connSQL.State == ConnectionState.Closed)
    {
        connSQL.Open();
    }
    sqlCmd.CommandType = CommandType.StoredProcedure;
    sqlCmd.CommandTimeout = 600;
    sqlCmd.Parameters.Add("@StartDate", SqlDbType.NVarChar).Value = "07/01/2010";
    sqlCmd.Parameters.Add("@EndDate", SqlDbType.NVarChar).Value = "07/31/2010";

    sqlCmd.Parameters.Add("@AuditType", SqlDbType.Int).Value = "0";

    sqlCmd.Parameters.Add("@SortBy", SqlDbType.NVarChar).Value = "";

    sqlCmd.Parameters.Add("@IsClaimDepartment", SqlDbType.NVarChar).Value = "true";
    sqlCmd.Parameters.Add("@IdsList", SqlDbType.NVarChar).Value = "";
    sqlCmd.Parameters.Add("@ReportType", SqlDbType.NVarChar).Value = "Top 20";
    sqlDataAdpater = new SqlDataAdapter(sqlCmd);
    sqlDataAdpater.Fill(returnData);
    if (connSQL.State == ConnectionState.Open)
    {
        connSQL.Close();
    }
    return returnData;
}
catch (Exception ex)
{
    LogErrorMessages("ExecuteStoredProcedure", ex.Message);
    throw ex;
}

Exception Received:

System.Data.SqlClient.SqlException: Timeout expired.  The timeout period elapsed prior to completion of the operation or the server is not responding.

Answer 1

Are you using any transactions in your stored procedure? Uncommitted transactions will cause this exact error message.

Answer 2

Try to a) reorganize your code, and b) increase the timeout:

DataTable returnData = null;

try
{
    using(SqlConnection connSQL = new SqlConnection(sqlConnection))
    using(SqlCommand sqlCmd = new SqlCommand("STORED_PROC_X", connSQL))
    {
       sqlCmd.CommandType = CommandType.StoredProcedure;
       sqlCmd.CommandTimeout = 1200;

       // those two parameters should really be SqlDbType.DateTime!!
       sqlCmd.Parameters.Add("@StartDate", SqlDbType.NVarChar, 25).Value = "07/01/2010";
       sqlCmd.Parameters.Add("@EndDate", SqlDbType.NVarChar, 25).Value = "07/31/2010";

       sqlCmd.Parameters.Add("@AuditType", SqlDbType.Int).Value = "0";

       sqlCmd.Parameters.Add("@SortBy", SqlDbType.NVarChar, 50).Value = "";

       // this parameter should really be SqlDbType.Bit !!
       sqlCmd.Parameters.Add("@IsClaimDepartment", SqlDbType.NVarChar, 50).Value = "true";

       sqlCmd.Parameters.Add("@IdsList", SqlDbType.NVarChar, 25).Value = "";
       sqlCmd.Parameters.Add("@ReportType", SqlDbType.NVarChar, 25).Value = "Top 20";

       SqlDataAdapter sqlDataAdpater = new SqlDataAdapter(sqlCmd);

       returnData = new DataTable();
       sqlDataAdpater.Fill(returnData);
   }

   return returnData;
}
catch (Exception ex)
{
   LogErrorMessages("ExecuteStoredProcedure", ex.Message);
   throw;
}

The SqlDataAdapter will open and close the connection itself - no need to do that explicitly.

Furthermore, I would

• define a sensible max length for your NVARCHAR parameters (what does the stored proc except)
• pass the dates as DATETIME ! (not NVARCHAR)
• pass the boolean value as BIT ! (not NVARCHAR)
• when you re-throw an exception, only use throw and not throw ex (if you use throw ex, you're basically breaking the stack trace and cannot figure out where the exception really came from)

Answer 3

Assuming that you are passing the same parameters from your code as when you are testing in SSMS and your SSMS test is exactly the same in terms of data type usage I would have thought this is likely to be a parameter sniffing issue.

Do you have access to SQL Profiler (doesn't come with Express edition) to get both actual execution plans? If not you can follow the advice in this answer to get the plans.