rand

Syntax

rand([integer])

Parameters

• integer – is any integer (tinyint, smallint, or int) column name, variable, constant expression, or a combination of these.

Examples

• Example 1 – Returns a random float value:

  select rand()

  --------------------
             0.395740

• Example 2 – Returns a random float value for a seed value of 100:

  declare @seed int
  select @seed=100
  select rand(@seed)

  -------------------- 
               0.000783 

Usage

The rand function uses the output of a 32-bit pseudorandom integer generator. The integer is divided by the maximum 32-bit integer to give a double value between 0.0 and 1.0. The rand function is seeded randomly at server start-up, so getting the same sequence of random numbers is unlikely, unless the user first initializes this function with a constant seed value.

The rand function is a global resource.

Multiple users calling the rand function progress along a single stream of pseudorandom values. If a repeatable series of random numbers is needed, the user must assure that the function is seeded with the same value initially and that no other user calls rand while the repeatable sequence is desired.

See also Transact-SQL Users Guide.

Standards

ANSI SQL – Compliance level: Transact-SQL extension.

Permissions

Any user can execute rand.