Php SQL SELECT查询导致不同的列错误

我正在尝试整理我的网站的邮件垃圾部分，结果证明很麻烦，我之前的查询有问题，最后终于让它工作了，但是现在分页也造成了麻烦，我得到了这个错误

Warning: mysql_fetch_array() expects parameter 1 to be resource, boolean given in C:\xampp\htdocs\Arken\pagination\function.php on line 9
SELECT COUNT(*) as `num` FROM user_inbox WHERE user_inbox.receiver_user_id='4' AND user_inbox.mail_deleted ='1' UNION SELECT * FROM user_outbox WHERE user_outbox.sender_user_id='4' AND user_outbox.mail_deleted ='1'

The used SELECT statements have a different number of columns

围绕第9行的代码如下所示

$query = "SELECT COUNT(*) as `num` FROM {$query}";
        $row = mysql_fetch_array(mysql_query($query)) or die($query."<br/><br/>".mysql_error());;
        $total = $row['num'];

+------------+---------------+------+-----+----------+
| Field             | Type          | Extra          |
+------------+---------------+------+-----+----------+
| message_id        | int(11)       | auto_increment |
| receiver_user_id  | int(11)                        |
| receiver_username | varchar(255)                   |
| sender_user_id    | int(11)                        |
| sender_username   | varchar(255)                   |
| mail_subject      | varchar(255)                   |
| mail_message      | text                           |
| mail_date_sent    | datetime                       |
| mail_viewed       | enum('0','1')                  |
| mail_deleted      | enum('0','1')                  |
+------------+---------------+------+-----+----------+

+------------+---------------+------+-----+----------+
| Field             | Type          | Extra          |
+------------+---------------+------+-----+----------+
| message_id        | int(11)       | auto_increment |
| sender_user_id    | int(11)                        |
| sender_username   | varchar(255)                   |
| receiver_user_id  | int(11)                        |
| receiver_username | varchar(255)                   |
| mail_subject      | varchar(255)                   |
| mail_message      | text                           |
| mail_date_sent    | datetime                       |
| mail_viewed       | enum('0','1')                  |
| mail_deleted      | enum('0','1')                  |
+------------+---------------+------+-----+----------+

我的user_outbox表如下所示

$query = "SELECT COUNT(*) as `num` FROM {$query}";
        $row = mysql_fetch_array(mysql_query($query)) or die($query."<br/><br/>".mysql_error());;
        $total = $row['num'];

+------------+---------------+------+-----+----------+
| Field             | Type          | Extra          |
+------------+---------------+------+-----+----------+
| message_id        | int(11)       | auto_increment |
| receiver_user_id  | int(11)                        |
| receiver_username | varchar(255)                   |
| sender_user_id    | int(11)                        |
| sender_username   | varchar(255)                   |
| mail_subject      | varchar(255)                   |
| mail_message      | text                           |
| mail_date_sent    | datetime                       |
| mail_viewed       | enum('0','1')                  |
| mail_deleted      | enum('0','1')                  |
+------------+---------------+------+-----+----------+

+------------+---------------+------+-----+----------+
| Field             | Type          | Extra          |
+------------+---------------+------+-----+----------+
| message_id        | int(11)       | auto_increment |
| sender_user_id    | int(11)                        |
| sender_username   | varchar(255)                   |
| receiver_user_id  | int(11)                        |
| receiver_username | varchar(255)                   |
| mail_subject      | varchar(255)                   |
| mail_message      | text                           |
| mail_date_sent    | datetime                       |
| mail_viewed       | enum('0','1')                  |
| mail_deleted      | enum('0','1')                  |
+------------+---------------+------+-----+----------+

我真的很感激你们能给我的任何帮助，我花了将近两天的时间来整理网站的这一部分，我需要把它完成。

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感谢您的反馈。

问题在于您使用UNION返回的列数不同

SELECT COUNT(*) as `num` FROM user_inbox ...
UNION
SELECT * FROM user_outbox ...

您可以让MySQL为您合计行数：

SELECT COUNT(*) AS `num`
FROM
(
     SELECT * FROM user_inbox ...
     UNION ALL
     SELECT * FROM user_outbox ...
) AS your_table_alias

或：

---

查询的第二部分（UNION之后）也应该有COUNT（*）

---

您应该对查询“$query”进行更多的研究。看起来您正在为PHP（我猜）代码中的变量“$query”定义的查询中选择不同数量的列（至少错误是这样说的）。

@MarkByers-不是两次。第一部分在收件箱中，第二部分在发件箱中。好的，对不起，我没有注意到。嗨，我尝试了你的答案，它似乎起了作用，但由于某种原因，它把所有的分页都弄乱了，所以例如，我有3个选项卡（收件箱、发件箱和垃圾箱）。如果垃圾箱有两页（分页），它会显示第一页，很好，但当我点击进入下一页时，它只是将我转移到“收件箱”选项卡，我的解决方案/答案应该是针对mysql错误的。请验证您的PHP分页逻辑。更新问题或发布带有分页逻辑的新问题。@user1136379:我认为这个答案不正确。你看过我的答案了吗？你为什么认为我的答案不正确？你能举一个失败的例子吗？