SQL查询语法从2个表中检索数据

Question

我在Mysql中有2个表格： authors和articles 。

我的作者每人都有几篇文章。

我需要使用此查询的结果进行sql查询：检索3个按年龄排序的作者，并且所有文章均属于他们。

在我的例子中

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

我用

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

结果错误

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

如果您只想包括在前3名最老的作者中写过任何文章的作者，请尝试在子查询中将作者与文章联系起来以获得3名最老的作者，然后使用DISTINCT来消除重复：

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