t-sql random string generator

Note: originally published in our old blog on December 2008.

CodeProject

This is a simple stored procedure that you can use to generate a random string. You can use it as a random password generator and for other purposes. It is very simple so I won't bore you with unnecessary explanations but if you do happen to have any questions feel free to post them here.

CREATE PROCEDURE [dbo].[usp_GenerateRandomString]
  @sLength tinyint = 10,
  @randomString varchar(50) OUTPUT
AS
BEGIN
  SET NOCOUNT ON
  DECLARE @counter tinyint
  DECLARE @nextChar char(1)
  SET @counter = 1
  SET @randomString = ''
  WHILE @counter <= @sLength
    BEGIN
      SELECT @nextChar = CHAR(ROUND(RAND() * 93 + 33, 0))
      IF ASCII(@nextChar) not in (34, 39, 40, 41, 44, 46, 96, 58, 59)
        BEGIN
          SELECT @randomString = @randomString + @nextChar
          SET @counter = @counter + 1
        END
    END
END