如果table1的值爲X，SQL更新table2？

Question

IF EXISTS (SELECT * FROM table1 WHERE group_id='8') 
UPDATE table2 SET (...) 
WHERE usertype='numbereight' 

我在做什麼錯？我需要根據GROUP_ID更新用戶類型

Answer 1

試試這個：

UPDATE table2 
SET someColumn = 'somevalue' 
WHERE EXISTS(SELECT * FROM table1 WHERE group_id='8') 
AND usertype='numbereight' 

Answer 2

你可以用這樣的嘗試：

UPDATE table2 
SET (...) 
WHERE usertype='number eight' AND EXIST(SELECT * FROM table1 WHERE group_id='8'); 

Answer 3

嘗試

UPDATE table2 
SET (...) 
WHERE usertype = 'numbereight' 
AND exists (select * from table1 where group_id = '8') 

Answer 4

你可以加入表格並更新您需要的任何字段

UPDATE t1 JOIN t2 ON t1.id = t2.id 
SET 
    t2.field = 'whatever' 
WHERE 
    t1.group_id= '8' AND 
    t2.usertype = 'numbereight'