php - mysql_num_rows 的问题

Question

出于某种原因，我无法理解我在 mysql_num_rows 方面遇到的麻烦。

脚本如下:

$notquery = 'SELECT * FROM notification WHERE uid = 1 AND read = 0 
AND tipo = post 
OR tipo = subpost OR tipo = logros';

$notQuery = (mysql_query($notquery));

$num_rows = mysql_num_rows($notQuery);

错误:

Warning:  mysql_num_rows(): supplied argument is not a valid MySQL result resource

Answer 1

这可能是因为您在查询执行过程中出现错误。
尝试添加 or die(mysql_error()) 来调试出现的问题...

将代码更新为:
$notQuery = mysql_query($notquery) 或 die(mysql_error());