Column name doesn't belong to table when getting results in DataRow using C#

Question

I am sure i have exact column name but when i try to get it using C# an error comes up that "Column name "TheoryCourseDate2" doesn't belong to table" I have stored procedure which gets count from another table and i save count results in my created Columns named "TheoryCourseDate1" and "TheoryCourseDate2"

Here is my stored procedure :

SELECT COUNT(NULLIF(dt_UserTTrainingDate1,'')) as TheoryCourseDate1 FROM ref_CourseRegistration_Users
SELECT COUNT(NULLIF(dt_UserTTrainingDate2,'')) as TheoryCourseDate2 FROM ref_CourseRegistration_Users

I get count results in code in DataRow and it works fine for column "TheoryCourseDate1" but not works for column "TheoryCourseDate2" even column name is correct. Here is C# Code :

SqlParameter[] parm = new SqlParameter[0];
DataRow oRow = SqlHelper.ExecuteRow(this._connString, CommandType.StoredProcedure, SQL_REF_GET_COUNT, parm);

if (oRow != null)
{
    oCourseCount.TheoryCourseDate1Count = Common.CheckStringNull(oRow["TheoryCourseDate1"]);
    oCourseCount.TheoryCourseDate2Count = Common.CheckStringNull(oRow["TheoryCourseDate2"]);
    return oCourseCount;
}

I am stuck with this as i dont think there is any error in my code etc but may be some other way can eliminate column name errors

Answer 1

You have two separate selects and so the results are not on the same row. Try this:

SELECT COUNT(NULLIF(dt_UserTTrainingDate1,'')) as TheoryCourseDate1,
  COUNT(NULLIF(dt_UserTTrainingDate2,'')) as TheoryCourseDate2 
FROM ref_CourseRegistration_Users