RANDOM

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

注意：所有参数必须为常量。

example

mysql> select random();
+---------------------+
| random()            |
+---------------------+
| 0.35446706030596947 |
+---------------------+

mysql> select rand(1.2);
+---------------------+
| rand(1)             |
+---------------------+
| 0.13387664401253274 |
+---------------------+
1 row in set (0.13 sec)

mysql> select rand(1.2);
+---------------------+
| rand(1)             |
+---------------------+
| 0.13387664401253274 |
+---------------------+
1 row in set (0.11 sec)

mysql> select rand(-20, -10);
+------------------+
| random(-20, -10) |
+------------------+
|              -13 |
+------------------+
1 row in set (0.10 sec)

keywords

RANDOM, RAND