Oracle更新基于另一个表中的值

Question

我有两张桌子ROOMS和LEASE，如下所述

create table ROOMS (ROOM_NUM number, FLOOR varchar2(50))
create table LEASE (ROOM_NUM number, RENT_RATE number(4,2))

我想将LEASE表中的rent_rate设置为3.50，用于ROOMS表中FLOOR ='Carpet'的所有房间。

我看过很多例子，但似乎无法提出解决方案。

我意识到我没有制作ROOM_NUM主键或外键，但我只是使用3条记录来测试问题，并确保两个表中都存在房间号

Answer 1

UPDATE LEASE
SET RENT_RATE = 3.5
WHERE ROOM_NUM IN (SELECT ROOM_NUM FROM ROOMS WHERE FLOOR='Carpet')

Answer 2

update lease
   set rent_rate = 3.50
where room_num in(select room_num from rooms where FLOOR='Carpet');

希望有所帮助。

Answer 3

并且，如果您需要创建行而不是更新现有行：

INSERT INTO LEASE
(SELECT ROOM_NUM, 3.5 FROM ROOMS WHERE FLOOR = 'Carpet');