SQL query syntax to retrieve data from 2 tables - mysql

Question

I have 2 tables in Mysql: authors and articles.
I have authors with several articles for each of them.
I need sql query with the result of this query:
retrieve 3 authors ordered by age with all articles which belong each of them.
In my example it will be
ID FIRSTNAME LASTNAME AGE AUTHORID TITLE PRICE
6 Salido Gomes 90 6 All 3 1
6 Salido Gomes 90 6 All 3 33
6 Salido Gomes 90 6 All 3 3
5 Vitora Mantora 45 5 Total 3 99
5 Vitora Mantora 45 5 Total 3 33
5 Vitora Mantora 45 5 Total 3 12
3 Joe Smith 43 3 Python 5
3 Joe Smith 43 3 Python 2 22
3 Joe Smith 43 3 Python 3 44
3 Joe Smith 43 3 Python 4 12
3 Joe Smith 43 3 Python 5 67
http://sqlfiddle.com/#!2/718c4/1
I use
select * from authors join articles on authors.id = articles.authorId
join (select authors.id from authors order by age DESC limit 3) as t
on t.id = authors.id
with wrong result
ID FIRSTNAME LASTNAME AGE AUTHORID TITLE PRICE
6 Salido Gomes 90 6 All 3 1
6 Salido Gomes 90 6 All 3 33
6 Salido Gomes 90 6 All 3 3

Answer 1

If you only want to include authors who have written any articles in the top 3 oldest authors try doing a join between authors and articles in the sub query to get the 3 oldest authors, and DISTINCT to eliminate duplicates:-
SELECT *
FROM
(
SELECT DISTINCT authors.id, authors.firstname, authors.lastname, authors.age
FROM authors
JOIN articles
ON authors.id = articles.authorId
ORDER BY authors.age
DESC
LIMIT 3
) author_sub
JOIN articles
ON author_sub.id = articles.authorId