Php mysql检查帖子是否被喜欢

我有三个表like，posts和users，在我的程序中，我通过用户id获取posts，当我这样做时，如果我喜欢posts或不喜欢posts，我想返回，我尝试这样做

$query="SELECT post , users.name, users.profile_pic , users.uid , posts.likes , posts.comments , posts.createdAt , posts.pid, 
            IF('$uid' IN (SELECT uid FROM likes WHERE uid='$uid' AND pid=this.posts.pid), 1, 0) AS i_liked
            FROM posts
            INNER JOIN users
            ON users.uid = posts.uid
            WHERE posts.uid = '$uid' OR posts.uid 
            IN (SELECT users.uid
                FROM friends
                INNER JOIN users
                ON users.uid=friends.ruid OR users.uid=friends.luid
                WHERE accept=1 AND (friends.luid='$uid' OR friends.ruid='$uid') AND users.uid!='$uid')

            ORDER BY posts.createdAt DESC
            LIMIT $loaded_posts, 20";

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但是它表明pid=this.posts.pid有一个错误。您需要将this.posts.pid更改为posts.pid。

在该上下文中这意味着什么…？我想指出当前处理的行查询中没有此项。拿着这个。它应该解决这个问题。“我想指出当前处理的行”-是什么让你认为它会这样工作…？