如何在WHERE子句中的mysql查询中得到if语句？

Question

有我在我的mysql查询中犯了错误。谁能帮我吗？？

select * from user_errors where user_id = '2' 
IF(type = 'custom_type') second_user_id != '2' ELSE second_user_id = '2' 
END IF 

Answer 1

没有必要使用if else，反正试试这个;）

select * from user_errors 
where user_id = '2' 
and ((type = 'custom_type' and second_user_id != '2') or second_user_id = '2') 

或者你必须使用它，试试这个;）

select * from user_errors 
where user_id = '2' 
and case when type = 'custom_type' then second_user_id != '2' else second_user_id = '2' end 

Answer 2

使用这样的（你不如果其他条件不需要使用）

select * from user_errors where user_id = '2' 
and ((type = 'custom_type' and second_user_id != '2') 
or (type != 'custom_type' and second_user_id = '2')) 

Answer 3

试试这个

select * from user_errors 
where user_id = '2' 
IF(type = 'custom_type', second_user_id != '2', second_user_id = '2') 

Answer 4

SELECT * FROM user_errors 
WHERE user_id = '2'AND (case when type = 'custom_type' then second_user_id != '2' else second_user_id = '2' end)