IF EXISTS(
   SELECT * FROM INFORMATION_SCHEMA.ROUTINES
   WHERE ROUTINE_NAME = ?ufProductsInCategory?)
DROP FUNCTION ufProductsInCategory
GO

CREATE FUNCTION ufProductsInCategory(@CategoryID AS int)
RETURNS int
AS
Начало
   RETURN(SELECT COUNT(*)
   FROM Northwind.dbo.Products AS np
   WHERE np.CategoryID = @CategoryID)
Конец
GO