SQL Server

Generating Random ASCII Strings

See more PRNG Examples

Demonstrates how to generate random us-ascii strings. SQL Server

-- Important: See this note about string length limitations for strings returned by sp_OAMethod calls.
--
CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    -- Important: Do not use nvarchar(max).  See the warning about using nvarchar(max).
    DECLARE @sTmp0 nvarchar(4000)
    DECLARE @success int
    SELECT @success = 0

    -- This example assumes the Chilkat API to have been previously unlocked.
    -- See Global Unlock Sample for sample code.

    SELECT @success = 0

    DECLARE @fortuna int
    EXEC @hr = sp_OACreate 'Chilkat.Prng', @fortuna OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    DECLARE @bDigits int

    DECLARE @bLowercase int

    DECLARE @bUppercase int

    -- Generate random strings having only lowercase chars (a-z)
    -- Disallow digits and uppercase and only allow lowercase
    SELECT @bDigits = 0
    SELECT @bUppercase = 0
    SELECT @bLowercase = 1

    DECLARE @i int


    PRINT '-- only lowercase alpha (a-z)'
    SELECT @i = 1
    WHILE @i <= 10
      BEGIN
        -- Generate 20-character strings.
        EXEC sp_OAMethod @fortuna, 'RandomString', @sTmp0 OUT, 20, @bDigits, @bLowercase, @bUppercase
        PRINT @sTmp0
        SELECT @i = @i + 1
      END

    -- Allow both lowercase and uppercase alpha chars
    SELECT @bUppercase = 1

    PRINT '-- lower and uppercase alpha (a-zA-Z)'
    SELECT @i = 1
    WHILE @i <= 10
      BEGIN
        -- Generate 20-character strings.
        EXEC sp_OAMethod @fortuna, 'RandomString', @sTmp0 OUT, 20, @bDigits, @bLowercase, @bUppercase
        PRINT @sTmp0
        SELECT @i = @i + 1
      END

    -- Allow digits (0-9)
    SELECT @bDigits = 1

    PRINT '-- digits and lower/uppercase alpha (0-9a-zA-Z)'
    SELECT @i = 1
    WHILE @i <= 10
      BEGIN
        -- Generate 20-character strings.
        EXEC sp_OAMethod @fortuna, 'RandomString', @sTmp0 OUT, 20, @bDigits, @bLowercase, @bUppercase
        PRINT @sTmp0
        SELECT @i = @i + 1
      END

    -- Allow only digits (0-9)
    SELECT @bUppercase = 0
    SELECT @bLowercase = 0

    PRINT '-- only digits (0-9)'
    SELECT @i = 1
    WHILE @i <= 10
      BEGIN
        -- Generate 20-character strings.
        EXEC sp_OAMethod @fortuna, 'RandomString', @sTmp0 OUT, 20, @bDigits, @bLowercase, @bUppercase
        PRINT @sTmp0
        SELECT @i = @i + 1
      END

    EXEC @hr = sp_OADestroy @fortuna


END
GO