sql与雇主表？薪水和advance_payment

Question

如何获得此付款？

employer_payment.payment = employer_salary.salary - employer_advance_payment.advance_payment

请就如何解决此问题向我提出建议？

Answer 1

您可以使用LEFT JOIN来计算salary扣除的advance_payment。

SELECT  a.employerID,
        a.salary - COALESCE(b.advance_payment, 0) payment
FROM    employer_salary a
        LEFT JOIN employer_advance_payment b
            ON a.employerID = b.employerID