Re: Minus function in Informix/SQL - How?

In article <412l98$cfm@news.informix.com>, Dennis Pimple <dennisp@informix.com> wrote: >Anish Maharaj (anish@cs.uct.ac.za) wrote: >: Hello, > >: I am using Informix-SQL to perform some benchmarks. I need to use a >: minus function but it appears that there is no standard minus function >: available in Informix. (i.e. a function to subtract one relation from >: another R1-R2). > >I was just successfully able to do this: > >SELECT cola - colb FROM table > >[...] > >Unless I don't know what you mean by a "minus function", this should >work. I suspect that what Anish is thinking of is something along these lines: select product_num, product_type from inventory MINUS select product_num, product_type from orders (i.e. show me all the <product_num, product_type> combinations that appear in the inventory table but don't appear in the orders table). I think that it isn't ASNI standard but it is part of Horracle's SQL*Plus. You can do the same thing with correlated subqueries I belive, details are left as an exercise for the reader (i.e. I know you can do it but I forget exactly how it goes). - Paul ** not a spokesman, etc **