从另一个表减去列的总和 - SQL select 语句

Question

I need help with this SQL statement.

I don't know how to get a null or zero for empty fields in subsalary column or how not to duplicate the records.

Answer 1

LEFT JOIN with GROUP BY will help:

SELECT T1.Emp_Id, T1.Safe_Id, T1.Salary,
       SUM(T2.SubSalary) AS SubSalary,
       (T1.Salary - SUM(T2.SubSalary)) AS [Difference]
FROM TableOne T1
LEFT JOIN TableTwo T2 ON T2.Emp_Id = T1.Emp_Id AND T2.Safe_Id = T1.Safe_Id
GROUP BY T1.Emp_Id, T1.Safe_Id, T1.Salary

Answer 2

something like this should do the trick

 SELECT t1.EmployeeID
    ,t1.safe_id
    ,MAX(t1.salary)
    ,SUM(COALESCE(t2.subSalary, 0)) AS SubSalary
    ,MAX(t1.salary) - SUM(COALESCE(t2.subSalary, 0)) AS difference
FROM Table1 t1
LEFT JOIN Table2 t2 ON t1.emp_id = t2.emp_id
    AND t1.safe_id = t2.safe_id
GROUP BY t1.EmployeeID
    ,t1.safe_id