Hey, I tried to create user defined function called Rank. which gets partition columns and order by column. this function should create rank according to its parameters. i.e.:
select customer, product, sales, Rank(customer, sales) from table should return: customerA productA 100 0 customerA productB 300 2 customerA productC 200 1 customerA productD 400 3 customerB productB 300 1 customerB productA 400 2 customerB productC 100 0 how can i do it? should i use FunctionType scalar or aggregate?
