随机选择表上的两个不同的行

Question

| postid | value | title   |
----------------------------
| 1      | 0     | Title 1 | 
| 2      | 1     | Title 2 | 
| 3      | 1     | Title 3 | 
| 4      | 0     | Title 4 | 
| 5      | 4     | Title 5 |

我试图从我的表中选择两个随机不同的行。有没有办法用SQL做到这一点？

我试过

SELECT postid
FROM table
WHERE postid > 0.9
ORDER BY RAND( )
LIMIT 2 

Answer 1

试试这个

SELECT DISTINCT postid 
FROM tablename
ORDER BY RAND()
LIMIT 2

Answer 2

是的，使用DISTINCT以及ORDER BY RAND()和LIMIT：

SELECT
  DISTINCT
  postid,
  value,
  title
FROM yourtable
ORDER BY RAND()
LIMIT 2