Php 小于运算符给出奇怪的结果

所以我用这个查询将两个表连接在一起并返回数据

SELECT * FROM userposts up
INNER JOIN userpostmeta upm
ON up.up_postID = upm.upm_postID
INNER JOIN userbasicprofile ubp
ON up.up_userID = ubp.ubp_userID
WHERE up.up_userID = :self OR up.up_userID IN (SELECT ufs_userID2 FROM userfriends where ufs_userID1 = :u)
AND
up.up_indexid < $startIndex AND up.up_indexid > 0
ORDER BY up.up_indexid DESC
LIMIT $limit

表userposts有一个名为'up_indexid'的列，它是自动递增的

问题是，当我为support 31发送$startIndex值时，它会显示indexid 31下方的帖子，但也会显示indexid 31上方的帖子

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为什么会这样？我尝试了多个断点，但似乎没有解决问题。

原因与尝试执行以下操作无关：

'SELECT * FROM userposts up
INNER JOIN userpostmeta upm
ON up.up_postID = upm.upm_postID
INNER JOIN userbasicprofile ubp
ON up.up_userID = ubp.ubp_userID
WHERE up.up_userID = :self OR up.up_userID IN (SELECT ufs_userID2 FROM userfriends where ufs_userID1 = :u)
AND
up.up_indexid < ' . intval($startIndex) . ' AND up.up_indexid > 0
ORDER BY up.up_indexid DESC
LIMIT ' . intval($limit)

我注意到您正在使用绑定和字符串内变量，为什么不也绑定startIndex和limit呢？ 此外，您可能希望了解抵消，在您的情况下，可能是一个更好的解决方案，例如限制100，10所以100个条目从第10个条目开始，根据或具有比WHERE子句更低的优先级，因此您的WHERE子句被解释为：

WHERE up.up_userID = :self OR (up.up_userID IN (SELECT ufs_userID2 FROM userfriends where ufs_userID1 = :u)
AND
up.up_indexid < $startIndex AND up.up_indexid > 0)
ORDER BY up.up_indexid DESC
LIMIT $limit

WHERE (up.up_userID = :self OR up.up_userID IN (SELECT ufs_userID2 FROM userfriends where ufs_userID1 = :u))
AND
up.up_indexid < $startIndex AND up.up_indexid > 0
ORDER BY up.up_indexid DESC
LIMIT $limit

我想你想要的是：

WHERE (up.up_userID = :self OR up.up_userID IN (SELECT ufs_userID2 FROM userfriends where ufs_userID1 = :u))
AND
up.up_indexid < $startIndex AND up.up_indexid > 0
ORDER BY up.up_indexid DESC
LIMIT $limit