MySql query limiting and ordering on join statamen

2019-08-03 08:14发布

问题:

I have a two tables as authors and articles. I want to get list of latest articles for each author. I want only one article for one author. And I want it to be the latest. But, I couldn't even figure out where to start to this sql query.

Edit

My table structure can be simplefied like this:

authors:
 id
 name
 status
 seo   
articles:
  author_id
  title
  text
  date
  seo

Edit 2

I came up with something like this, is there any obvious mistakes you can see in here:

SELECT authors.*, 
(SELECT articles.title FROM articles WHERE author_id = authors.id ORDER BY articles.date DESC LIMIT 1) as title,
(SELECT articles.seo FROM articles WHERE author_id = authors.id ORDER BY articles.date DESC LIMIT 1) as articleseo 
FROM authors 
WHERE authors.status = 1

回答1:

No clue what your table structure is, but if it's what I envision then do this:

SELECT author.name, article.title FROM
    author LEFT JOIN article ON author.id = article.author_id
    GROUP BY author.id
    ORDER BY author.id, article.date DESC


回答2:

Alright, I found out what I needed to do:

CREATE TEMPORARY TABLE articles2
SELECT max(date) as maxdate, author_id
FROM articles
GROUP BY author_id;

SELECT authors.name, authors.seo, articles.seo, articles.title FROM articles JOIN articles2 ON (articles2.author_id = articles.author_id AND articles2.maxdate = articles.date) JOIN authors on authors.id = articles.author_id WHERE authors.status = 1

I hope this helps someone.



回答3:

I'll do something like that, but if you post the database structure I'll be more specific

    SELECT * 
    FROM articles,authors 
    WHERE articles.aut = authors.aut
    GROUP BY authors.aut 
    ORDER BY articles.date DESC