sql'is not'(<>)不起作用 [英] sql 'is not' ( <> ) is not working

问题描述

我不知道我做错了什么...这是我的代码:

I have no idea what I do wrong... this is my code:

SELECT *
FROM messages
WHERE userId = "6"
OR toUserId = "6"
OR toAll = "1"
AND id <> "4"
ORDER BY time DESC
LIMIT 1

问题是'is not'(<>)不起作用，它仍返回id为4的结果.有什么问题?

The problem is that the 'is not' (<>) is not working, it still returns a result where id is 4. What's the problem?

现在我遇到了以下问题:

Now I'm stuck with the following problem:

SELECT *
FROM messages
WHERE (
    userId = "6"
    OR toUserId = "6"
    OR toAll = "1"
)
AND id <> IN ('4','2')
ORDER BY time DESC
LIMIT 1

同样的问题是输出为假，这意味着它不起作用.

And again the problem is that the output is false, meaning this doesn't work.

推荐答案

您需要使用括号来表示运算符优先级:

You need to use parenthesis to indicate operator precedence:

WHERE (
       userId   = "6"
    OR toUserId = "6"
    OR toAll    = "1"
)
AND id <> "4"

这篇关于sql'is not'(&lt;&gt;)不起作用的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！