Question

Mysql查询

select t.text from topic t 
inner join tag tg on tg.topic_id = t.id where tg.id in (3,4,5,6,7)

现在我如何从IN子句中匹配的最大值到最小值来订购这些结果。

更新 - 在那些建议添加order by tg.id desc的人之间 - 请不要误解它的标签ID的个别值而不是IN子句中匹配的值的数量。

Answer 1

您应该使用topic_id表格中的tag分组来加入您的表格，如下所示：

select t.text from topic t 
inner join
 (SELECT topic_id, COUNT(id) tags_count
   FROM tag WHERE id IN (3,4,5,6,7)
   GROUP BY topic_id
 ) tg on tg.topic_id = t.id
ORDER BY tg.tags_count DESC

Answer 2

试试这个

select t.text from topic t 
inner join tag tg on tg.topic_id = t.id where tg.id in (3,4,5,6,7)
order by tg.id desc

IN子句的mysql顺序最大匹配

2 个答案: