random

description

Syntax

DOUBLE random() 返回0-1之间的随机数。

DOUBLE random(DOUBLE seed) 返回0-1之间的随机数，以seed作为种子。

BIGINT random(BIGINT a, BIGINT b) 返回a-b之间的随机数，a必须小于b。

别名：rand

example

1. mysql> select random();
2. +---------------------+
3. | random()            |
4. +---------------------+
5. | 0.35446706030596947 |
6. +---------------------+

8. mysql> select rand(1.2);
9. +---------------------+
10. | rand(1)             |
11. +---------------------+
12. | 0.13387664401253274 |
13. +---------------------+
14. 1 row in set (0.13 sec)

16. mysql> select rand(1.2);
17. +---------------------+
18. | rand(1)             |
19. +---------------------+
20. | 0.13387664401253274 |
21. +---------------------+
22. 1 row in set (0.11 sec)

24. mysql> select rand(-20, -10);
25. +------------------+
26. | random(-20, -10) |
27. +------------------+
28. |              -13 |
29. +------------------+
30. 1 row in set (0.10 sec)

keywords

1. RANDOM, RAND