php - 如果 NOT IN 中的值为空，则 mysql 会抛出错误

Question

如果 m.message_type_id IN () 为空，则会出现错误

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ') ) UNION ( ' at line 16

        SELECT m.id,m.log,message,images,videos,uo.user_id as to_id,owner_id,
        IF(m.owner_id = 45,'sent','received') as type
        FROM messages as m 
        LEFT JOIN events as e ON m.message_type_id = e.id
        LEFT JOIN user_organization as uo ON uo.id = e.org_id
        WHERE m.message_type_id IN ()
        AND m.type = 'event_invite_request_msg'

如果 WHERE m.message_type_id IN (61) 它会给我正确的响应。

解决办法是什么？

Answer 1

IN 子句期望您至少发送一个值，为什么您期望它即使使用空参数也能工作？

expr NOT IN (value,...)

<强> Syntax

从更广泛的角度来看，几乎所有比较都是这种情况，如果要比较的值无效，为什么您会期望比较不会导致错误

这对你有用吗？

SELECT myField FROM myTable WHERE MyField2 = 

不，不会