SQL查询在PHP中返回与MySQL Shell中的结果不同的结果

Question

这个问题源于一个较早的问题 。

当我在mysql shell上运行此脚本时（见下文）

 mysql> SELECT -> t1.post_id, -> 'multiple' AS multiple, -> COUNT(*) as count -> FROM people_publication AS t1 GROUP BY t1.post_id -> UNION -> SELECT -> t2.post_id, -> REPLACE( -> CONCAT( -> 'multiple_', -> @curRow:=CASE -> WHEN @postId = t2.post_id THEN @curRow + 1 -> ELSE 0 -> END, -> @postId:=t2.post_id -> ), -> t2.post_id, -> '' -> ) AS multiple, -> t2.pid -> FROM people_publication AS t2 -> ORDER BY post_id, multiple; +---------+------------+-------+ | post_id | multiple | count | +---------+------------+-------+ | 7209 | multiple | 3 | | 7209 | multiple_0 | 27 | | 7209 | multiple_1 | 34 | | 7209 | multiple_2 | 1 | | 7210 | multiple | 3 | | 7210 | multiple_0 | 51 | | 7210 | multiple_1 | 11 | | 7210 | multiple_2 | 37 | | 7211 | multiple | 1 | | 7211 | multiple_0 | 36 | | 7212 | multiple | 1 | | 7212 | multiple_0 | 11 | | 7213 | multiple | 1 | | 7213 | multiple_0 | 15 | | 7215 | multiple | 1 | | 7215 | multiple_0 | 42 | +---------+------------+-------+ 16 rows in set (0.00 sec) 

当我使用php运行相同的脚本时，我得到的结果不同

 $query = "SELECT t1.post_id, 'multiple' AS multiple, COUNT(*) as count FROM people_publication AS t1 GROUP BY t1.post_id UNION SELECT t2.post_id, REPLACE( CONCAT( 'multiple_', @curRow:=CASE WHEN @postId = t2.post_id THEN @curRow + 1 ELSE 0 END, @postId:=t2.post_id ), t2.post_id, '' ) AS multiple, t2.pid FROM people_publication AS t2 ORDER BY post_id, multiple"; $sql=$con->prepare($query); $sql->execute(); $sql->setFetchMode(PDO::FETCH_ASSOC); while($row=$sql->fetch()){ echo "<pre>";print_r($row); } 

它返回一个看起来像这样的表（见下文）

 +---------+---------+------------+------------+ | meta_id | post_id | meta_key | meta_value | +---------+---------+------------+------------+ | 816 | 7209 | multiple | 3 | | 817 | 7209 | multiple_0 | 34 | | 818 | 7209 | multiple_0 | 1 | | 819 | 7209 | multiple_0 | 27 | | 820 | 7210 | multiple | 3 | | 821 | 7210 | multiple_0 | 37 | | 822 | 7210 | multiple_0 | 51 | | 823 | 7210 | multiple_0 | 11 | | 824 | 7211 | multiple | 1 | | 825 | 7211 | multiple_0 | 36 | | 826 | 7212 | multiple | 1 | | 827 | 7212 | multiple_0 | 11 | | 828 | 7213 | multiple | 1 | | 829 | 7213 | multiple_0 | 15 | | 830 | 7215 | multiple | 1 | | 831 | 7215 | multiple_0 | 42 | +---------+---------+------------+------------+ 

是什么原因导致这种情况发生？

连接文件如下所示

 <?php //session_start(); function dbConnect() { $host = 'localhost'; $dbname = 'mydb'; $user = 'root'; $pass = ''; try { $con= new PDO("mysql:host=$host;dbname=$dbname", $user, $pass); return $con; $con->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); } catch (PDOException $e) { echo 'Cannot connect to database'; exit(); } }?> 

Answer 1

请检查您的php代码中的mysql连接类

还有一件事要检查在localhost mysql上是否使用套接字连接，而在服务器上使用端口连接。 如果它们是不同实例，可能会导致问题