如果我正在更新一个页面,我首先检查是否为今天设置了一个条目,如果没有,我会选择一个在数据库中存在时间最长的条目,如下所示: $result=mysql_query("SELECT * FROM amazingjokes.img WHERE isnull(listed)ORDER BY added ASC");
$row=
od_form_items; +----------+ | count(*) | +----------+ | 180 | +----------+ 1 row in set (0.00 sec)mysql> select length(items) as a from qiban.od_form_items order by a desc limit 1; +-------+slow_log中,选择所有记录占用了2秒:
mysql> select start_time, query