Since the NEWID() function is a non-deterministic function, this function cannot be called directly from a user-defined function. One way to work around this limitation is to call the function indirectly through a view.
First create a view that calls the NEWID() function:
CREATE VIEW [dbo].[Random]
AS
SELECT NEWID() AS [RandomID]
Since a view can be accessed from a user-defined function, a function can now be created that will indirectly call the NEWID() function through the view:
CREATE FUNCTION [dbo].[ufn_GenerateRandomNumber]()
RETURNS INT
AS
BEGIN
DECLARE @RandomNumber INT
SELECT @RandomNumber = ABS(CAST(CAST([RandomID] AS VARBINARY) AS INT))
FROM [dbo].[Random]
RETURN @RandomNumber
END
Now to use this user-defined function that calls the NEWID() function indirectly:
SELECT [dbo].[ufn_GenerateRandomNumber]()