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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