[英]MySQL case in where clause
I'm having problems with a suspected logic error with a CASE statement in my WHERE clause but I can't see the problem. 我的WHERE子句中的CASE语句存在可疑的逻辑错误,但我看不到问题。
SELECT a_id, a_name, a_folder_flag
FROM table_a
LEFT JOIN table_b ON table_a.a_id = table_b.b_a_id
WHERE a_status_id = 1
AND (
CASE
WHEN a_access_flag = 1
THEN b_usr_id = 1 OR b_grp_id = 2
END )
GROUP BY a_id
Basically I want to get all records from table_a
but if a_access_flag
is 1
then I need to apply the additional where clause filtering in the CASE statement. 基本上,我想从
table_a
获取所有记录,但是如果a_access_flag
为1
则需要在CASE语句中应用其他where子句过滤。
Currently it is returning 0 rows when I include the CASE statement. 目前,当我包含CASE语句时,它返回0行。
A case
does not make much sense in a where
clause. 在
where
子句中, case
没有多大意义。 But you can convert that into logic. 但是您可以将其转换为逻辑。 Try
尝试
WHERE a_status_id = 1
AND
(
a_access_flag <> 1
OR (b_usr_id = 1 OR b_grp_id = 2)
)
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