Mysql查询GROUP BY条件LIMIT 1

Question

I have a table called "articles" on the database

articles :

id +++   writer_id    +++     title     ++++    text
----------------------------------------------------
1           1              some title        article for writer 1 
2           1              some title        article for writer 1 
3           2              some title        article for writer 2 
4           2              some title        article for writer 2 
5           2              some title        article for writer 2
6           3              some title        article for writer 3

I need a query to get the latest articles from the table BUT just ONE article for each Writer

depends on the rows above the query should get just 3 rows : each article owns by ONE writer

2           1              some title        article for writer 1 
5           2              some title        article for writer 2
6           3              some title        article for writer 3

php

SELECT * 
FROM articles
WHERE writer_id = ???? ;
order by id desc limit 10

thanks in advance : )

Answer 1

Using a combination of GROUP BY and HAVING will allow you to get the last article written by each author, and have them ordered properly:

SELECT * 
FROM articles
WHERE writer_id = ????
GROUP BY writer_id
HAVING id = MAX(id)
ORDER BY id DESC
LIMIT 10

Answer 2

短而甜蜜：

SELECT MAX(id), writer_id, title, text FROM articles GROUP BY writer_id;

Answer 3

Use a subquery to get the latest article id per writer:

SELECT * FROM articles
WHERE id in
(
    SELECT MAX(id) id, writer_id
    FROM articles
    GROUP BY writer_id
)