求一个update join的问题
a表:id，money
b表:id,meony
a的id唯一，b的id可重复，b的id一定存在于a中

要求a.money=sum(b.money) group by b.id
[解决办法]
UPDATE A SET A.money = (SELECT SUM(money) FROM B WHERE A.ID = B.ID GROUP BY B.ID )
[解决办法]
UPDATE A SET A.money = (SELECT SUM(money) FROM B WHERE A.ID = B.ID GROUP BY B.ID )
where exists (select 1 from A.ID = B.ID);