Question

我遇到了一个小问题。我有以下代码：

    $query = $db->prepare('(SELECT last_visit, last_ip FROM user_log WHERE user_id = :id) 
                            UNION
                           (SELECT time AS last_visit, packet_hex AS last_ip FROM crack_log WHERE target_id = :id)
                            ORDER BY last_visit DESC LIMIT 0,10;');
    $query->execute(array(':id'=> $_SESSION['id']));
    $log = $query->fetchAll(PDO::FETCH_ASSOC); //Last visit/IP

    var_dump($log);

返回：

array(0) { }

我在phpmyadmin中尝试了查询，但它运行正常。能帮我找到错误吗？

Answer 1

Accorrding to the documentation

您不能在a中两次使用同名的命名参数标记准备好的声明您无法将多个值绑定到for中的单个命名参数例如，SQL语句的IN（）子句。

在你的情况下，你应该使用像

这样的东西

$query = $db->prepare('(SELECT last_visit, 
                               last_ip 
                        FROM user_log 
                        WHERE user_id = :id_1
                       ) 
                        UNION
                       (SELECT time AS last_visit,
                               packet_hex AS last_ip 
                        FROM crack_log 
                        WHERE target_id = :id_2
                       )
                       ORDER BY last_visit DESC LIMIT 0,10;'
                     );
    $query->execute(array(':id_1'=> $_SESSION['id'],
                          ':id_2'=> $_SESSION['id'] 
                         )
                   );

PDO提取不返回任何内容

1 个答案: