如何对两个表的不同列减法进行 Oracle DB 查询

Question

CREATE TABLE member (
member_no   NUMBER  PRIMARY KEY ,
member_money NUMBER NOT NULL,
);
CREATE TABLE MY_PAY(
pay_no NUMBER PRIMARY KEY,
member_no NUMBER,
pay_price number
);

我想要 MEMBER.member_money -(MINUS) MY_PAY.pay_price =?? 和 ？？ 插入 MEMBER.member_money

所以我做这个查询

UPDATE MEMBER
set MEMBER.member_money = (select sum (MEMBER.member_point) - (MY_PAY.pay_price)
from MY_PAY
where MY_PAY.member_no = MEMBER.member_no
group by MEMBER.member_no)
where MEMBER.member_no =2 ;

但它不起作用。 我不是英国人，所以我不擅长英语对不起，但我需要你的帮助

Answer 1

您可以使用：

UPDATE MEMBER m
set member_money = member_money - (select sum(pay_price)
                                   from   MY_PAY p
                                   where  p.member_no = m.member_no)
where  member_no =2 ;

其中，对于样本数据：

INSERT INTO member VALUES (2, 2000);

INSERT INTO my_pay
SELECT 1, 2, 100 FROM DUAL UNION ALL
SELECT 2, 2, 200 FROM DUAL;

然后，在UPDATE ：

SELECT * FROM member;

输出：

MEMBER_NO	MEMBER_MONEY
2	1700

db<> 在这里摆弄