甲骨文更新

Question

我有兩個表的客房和租賃低於

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

描述我想在租約表rent_rate設定爲3.50對於所有的房間有樓='地毯'在ROOMS表中。

我看了很多例子，但似乎無法提出解決方案。

我意識到，我沒有讓ROOM_NUM主鍵和外鍵，但我只是用3個記錄測試的問題，確保了兩個表中存在，他們的房間號碼

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'); 

希望這有助於。

Answer 3

而且，如果你需要創建行而不是更新現有行：

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