如何从20个最近的行中选择5个随机行？

Question

我想从一个表中选择5个随机行，但只从最近的20个行中选择。我知道这两个陈述分别是：

SELECT * FROM table ORDER BY RAND() LIMIT 5
SELECT * FROM table ORDER BY date DESC LIMIT 20

我如何组合这两个语句，以便从20个最近的行中选择5个随机行？感谢。

Answer 1

使用嵌套选择

 SELECT foo.* FROM (SELECT * FROM table ORDER BY date DESC LIMIT 20 ) as foo 
         ORDER BY RAND() LIMIT 5

Answer 2

简单地嵌套它们：

SELECT * FROM (
    SELECT * FROM table ORDER BY date DESC LIMIT 20
) ORDER BY RAND() LIMIT 5

Answer 3

查找子查询！

SELECT d.* FROM (SELECT * FROM table ORDER BY date DESC LIMIT 20) as d ORDER BY RAND() LIMIT 5;