Das ist die Abfrage, die ich zu schreiben versucht habe
select posts.* ,users.* FROM posts INNER JOIN users ON posts.user_id = users.id WHERE posts.user_id != '27' AND posts.pid EXISTS(SELECT post_id FROM favourites WHERE posts.pid=favourites.post_id)
Das ist ein Fehler
select posts.* ,users.* FROM posts INNER JOIN users ON posts.user_id = users.id WHERE posts.user_id != '27' AND posts.pid EXISTS(SELECT post_id FROM favourites WHERE posts.pid=favourites.post_id) LIMIT 0, 25 MySQL said: Documentation #1064 - You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'EXISTS(SELECT post_id FROM favourites WHERE posts.pid=favourites.post_id) LIM...' at line 6
![[Web-Frontend] Node.js-Schnellstart](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
您必须使用
IN而不是 ÈXISTS。exists 的语法不同
SELECT posts.*, users.* FROM posts INNER JOIN users ON posts.user_id = users.id WHERE posts.user_id != '27' AND posts.pid IN (SELECT post_id FROM favourites WHERE posts.pid = favourites.post_id) LIMIT 0 , 25这将检查是否有一个最喜欢的帖子 id
SELECT posts.*, users.* FROM posts INNER JOIN users ON posts.user_id = users.id WHERE posts.user_id != '27' AND EXISTS (SELECT post_id FROM favourites WHERE posts.pid = favourites.post_id) LIMIT 0 , 25