Question

我正在尝试按时间和日期排序邮件，但它不起作用：这是我的代码：

$sql="SELECT id, message, sender, recipient, date, time, IF(recipient = ".$_SESSION["user"]["id"].", 'received', 'sent') AS direction
        FROM message
        WHERE
            (recipient = $friend_id OR sender = $friend_id)
            AND id > $last_message_id ORDER BY time AND date ASC";

Answer 1

您的语法略有偏差。多列的排序规范需要以逗号分隔。试试这个：

$sql="SELECT id, message, sender, recipient, date, time, IF(recipient = ".$_SESSION["user"]["id"].", 'received', 'sent') AS direction
        FROM message
        WHERE
            (recipient = $friend_id OR sender = $friend_id)
            AND id > $last_message_id ORDER BY time ASC, date ASC";

作为旁注，ASC是默认的排序顺序，因此您无需明确指定它。

Answer 2

它应该是ORDER BY time ASC, date ASC，假设两者都是适当的数据类型;如果它们是字符串类型，它并不总是按照需要运行。

Answer 3

你需要将ASC与这两个栏目放在一起： -

$sql="SELECT id, message, sender, recipient, date, time, IF(recipient = ".$_SESSION["user"]["id"].", 'received', 'sent') AS direction
        FROM message
        WHERE
            (recipient = $friend_id OR sender = $friend_id)
            AND id > $last_message_id ORDER BY time ASC, date ASC";

按日期和时间排序的SQL顺序不起作用

3 个答案: