Question

我想在我的SQL查询的WHERE子句中使用IF条件。但比较应该来自另一个表格的列。简单地说，我的伪代码是这样的：

SELECT * FROM TABLE1
WHERE
 (if DATE from TABLE2 = 0000 then select ID from TABLE2 as TABLE1.ID 
 else if ID from TABLE2 = 00 then select DATE from table2 as TABLE1.DATE)

感谢您的帮助。

Answer 1

你的伪代码很模糊，但据我所知，这样的东西应该有效：

SELECT TABLE1.* 
FROM TABLE1
INNER JOIN TABLE2 
   ON   (TABLE2.DATE = '0000' AND TABLE1.ID = TABLE2.ID)
     OR (TABLE2.ID = '00' AND TABLE2.DATE = TABLE1.DATE)

请参阅this fiddle。

If / Else in SQL Where子句

1 个答案: