sql - 带有雇主表的sql？工资和预付款

Question

如何获得这笔款项？

employer_payment.payment = employer_salary.salary - employer_advance_payment.advance_payment

请就我如何解决这个问题的问题给我你的建议？

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