mysql - GROUP BY 得到前两行

Question

所以我有以下查询，它按照我的预期执行。它从每个作者那里获取最新发表的文章。但是现在我想让它从每个作者那里得到最新的两篇文章。我该怎么做？

SELECT author_article.ID
FROM (
       SELECT
         sorted_articles.ID,
         sorted_articles.AuthorID,
         sorted_articles.PublishedDate
       FROM ArticlePage sorted_articles
       ORDER BY PublishedDate DESC
     ) author_article
GROUP BY author_article.AuthorID
ORDER BY author_article.PublishedDate DESC;

所以我需要的是每个作者的最新 2 篇文章。

Answer 1

使用相关子查询来计算同一作者最近发表的所有文章。如果有 1 篇或更少的最新文章，则返回该行。

SELECT *
FROM ArticlePage t1
WHERE (select count(*) from ArticlePage t2
       where t2.AuthorID = t1.AuthorID
         and t2.PublishedDate > t1.PublishedDate) <= 1