如何從20個最近的行中選擇5個隨機行？

Question

我想從表中選擇5個隨機行，但只能從最近的20行中選擇。我知道2個報表中單獨會是這樣的：

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

我將如何結合這2所陳述所以它會選擇最近的20排5個隨機行？謝謝。

Answer 1

使用嵌套查詢

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

Answer 2

只需將其嵌套：

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

Answer 3

查找子查詢！

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