在sql查询中按问题排序会给出语法错误

Question

我在这里有这个问题：

$query_pag_data = "SELECT 
matching.date,
matching.points,
matching.time,
matching.location,
matching.epos_id,
matching.time_added,
rbpos_epos.epos_id,
rbpos_epos.location
FROM
matching
LEFT JOIN
rbpos_epos ON matching.epos_id = rbpos_epos.epos_id
WHERE
matching.user_id = ".$id_user." LIMIT $start, $per_page ORDER BY matching.time_added DESC";

我在ORDER BY部分出错，出了什么问题，我应该把它放在哪里？ ...

Answer 1

您已经交换了ORDER BY和LIMIT子句的顺序。首先是ORDER BY子句，然后是LIMIT子句。这应该有效：

$query_pag_data = "SELECT 
matching.date,
matching.points,
matching.time,
matching.location,
matching.epos_id,
matching.time_added,
rbpos_epos.epos_id,
rbpos_epos.location
FROM
matching
LEFT JOIN
rbpos_epos ON matching.epos_id = rbpos_epos.epos_id
WHERE
matching.user_id = ".$id_user." ORDER BY matching.time_added DESC LIMIT ".$start.", ".$per_page;

Answer 2

限制总是在结果收集结束时应用，因此在按顺序排列后。

鉴于你的所有条款，处理顺序将是

• FROM
• WHERE
• 选择
• ORDER BY
• LIMIT

因此，您将获得最接近的记录＆lt; = publishedOn匹配WHERE子句中的所有条件。

@credit：RichardTheKiwi