如果 NOT IN 中的值为空 mysql 则抛出错误

Question

如果 m.message_type_id IN () 为空，它会给我一个错误提示

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) 它给了我正确的响应。

解决方法是什么？

Answer 1

IN 子句要求您至少发送一个值，为什么您希望即使参数为空也能正常工作？

expr NOT IN (value,...)

Syntax

在更广泛的层面上，几乎所有比较都是这种情况，如果有无效值要与之比较，你为什么期望比较不会导致错误

这对你有用吗？

SELECT myField FROM myTable WHERE MyField2 =

不会的

Answer 2

你必须为此使用条件

if(count($friendsArray[])){
        $qry = "SELECT m.id,m.log,message,images,videos,uo.user_id as to_id,owner_id,
        IF(m.owner_id = 45,'sent','received') as type
        FROM messages as m 
        LEFT JOIN events as e ON m.message_type_id = e.id
        LEFT JOIN user_organization as uo ON uo.id = e.org_id
        WHERE m.message_type_id IN ($ids)
        AND m.type = 'event_invite_request_msg'";
}else{
        $qry = "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.type = 'event_invite_request_msg'";
}

如果 NOT IN 中的值为空 mysql 则抛出错误

If the value inside NOT IN is empty mysql is throwing an error

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