MySQL Tutorial/Math Numeric Functions/RAND

RAND(20)

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SELECT RAND(20); +------------------+ | RAND(20) | +------------------+ | 0.15888261251047 | +------------------+ 1 row in set (0.00 sec) mysql> mysql> SELECT RAND(20); +------------------+ | RAND(20) | +------------------+ | 0.15888261251047 | +------------------+ 1 row in set (0.00 sec) mysql></source>

RAND(), RAND(N) returns a random floating-point value v in the range 0

If a constant integer argument N is specified, it is used as the seed value, which produces a repeatable sequence of column values.

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mysql> mysql> SELECT RAND(); +------------------+ | RAND() | +------------------+ | 0.72570215698863 | +------------------+ 1 row in set (0.00 sec) mysql> mysql> SELECT RAND(20); +------------------+ | RAND(20) | +------------------+ | 0.15888261251047 | +------------------+ 1 row in set (0.00 sec) mysql> mysql> SELECT RAND(20); +------------------+ | RAND(20) | +------------------+ | 0.15888261251047 | +------------------+ 1 row in set (0.00 sec) mysql> mysql> SELECT RAND(); +------------------+ | RAND() | +------------------+ | 0.49934750655605 | +------------------+ 1 row in set (0.00 sec) mysql> mysql> SELECT RAND(); +------------------+ | RAND() | +------------------+ | 0.31963109254803 | +------------------+ 1 row in set (0.00 sec)</source>

To obtain a random integer in the range the range 7

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mysql> mysql> SELECT FLOOR(7 + (RAND() * 5)); +-------------------------+ | FLOOR(7 + (RAND() * 5)) | +-------------------------+ | 7 | +-------------------------+ 1 row in set (0.00 sec) mysql></source>