本文章给大家介绍MySQL获取所有分类和每个分类的前N条记录,Article(Id,Category,InsertDate),现在要用SQL找出每种类型中时间最新的前N个数据组成的集合,一段不错的代码,代码如下:
- SELECT A1.*
- FROM Article AS A1
- INNER JOIN (SELECT A.Category,A.InsertDate
- FROM Article AS A
- LEFT JOIN Article AS B
- ON A.Category = B.Category
- AND A.InsertDate <= B.InsertDate
- GROUP BY A.Category,A.InsertDate
- HAVING COUNT(B.InsertDate) <= @N
- ) AS B1
- ON A1.Category = B1.Category
- AND A1.InsertDate = B1.InsertDate
- ORDER BY A1.Category,A1.InsertDate DESC
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