mysql - 这种情况如何查询呢？

Question

我写了一个question几个小时前关于多对多查询。 Mellamokb 建议:

How about list the categories, and how many posts in each category, sorted from the category with the most posts to the category with the least.

我实际上如何制作查询字符串？我什至不知道从哪里开始。

Answer 1

那么...这是您正在寻找的东西吗？

    SELECT category.name
         , COUNT(*) as [Count]
      FROM post
INNER JOIN postcategory ON post.id = postcategory.post_id
INNER JOIN category ON postcategory.category_id = category.id
  ORDER BY count
  GROUP BY category.name