Solved!! Column is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause

If Group By gives you an error the e.g (I got an error - Column 'Employee.EmpID' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause.)


Answer: Chances are that all the values in the column selected are unique and there is nothing to group by with/on. Group By works when there is data that resembles each other, then Group by will go and group those data value.