Is this sql syntax correct?

Can i apply SUM() within an ISNULL().... Consider my fo开发者_如何学编程llowing sql server select statement

SELECT e.Emp_Id,e.Identity_No,e.Emp_Name,case WHEN e.SalaryBasis=1 
THEN 'Weekly' ELSE 'Monthly' end as SalaryBasis,e.FixedSalary,
    ISNULL(Adv.Daily_Wage,0) as Advance from Employee as e 
    inner join Designation as d on e.Desig_Id=d.Desig_Id
    Left Outer Join Payroll as Adv on e.Emp_Id=Adv.Emp_Id where e.Is_Deleted=0 

This Statement Works fine.... But when i apply SUM() within an ISNULL()

SELECT e.Emp_Id,e.Identity_No,e.Emp_Name,case WHEN e.SalaryBasis=1 
    THEN 'Weekly' ELSE 'Monthly' end as SalaryBasis,e.FixedSalary,
        ISNULL(SUM(Adv.Daily_Wage),0) as Advance from Employee as e 
        inner join Designation as d on e.Desig_Id=d.Desig_Id
        Left Outer Join Payroll as Adv on e.Emp_Id=Adv.Emp_Id 
        where e.Is_Deleted=0 

I got the error,

Column 'Employee.Emp_Id' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause.

Any suggestion....

You need to GROUP BY the other columns in the select. Something like

SELECT  e.Emp_Id,
        e.Identity_No,
        e.Emp_Name,
        case 
            WHEN e.SalaryBasis=1  THEN 'Weekly' 
            ELSE 'Monthly' 
        end as SalaryBasis,e.FixedSalary, 
        ISNULL(SUM(Adv.Daily_Wage),0) as Advance 
from    Employee as e  inner join 
        Designation as d on e.Desig_Id=d.Desig_Id Left Outer Join 
        Payroll as Adv on e.Emp_Id=Adv.Emp_Id  
where   e.Is_Deleted=0 
GROUP BY e.Emp_Id, --This section is what you are missing
        e.Identity_No,
        e.Emp_Name,
        case 
            WHEN e.SalaryBasis=1  THEN 'Weekly' 
            ELSE 'Monthly' 
        end,
    e.FixedSalary

Have a look at the definition here

GROUP BY (Transact-SQL)