Group certain columns then chose a First/Last entry in one of the columns

[MILOS PROKIC]

Hi! I'm quite new to MySQL, but I have some experience with MS Access.

I am looking to perform a Select statement within a View with a Group By option on 3 columns. On the 4th column, I'm looking to take the FIRST or LAST occurrence.

The Select statement is not run on a table, rather it is run on a View.

The initial View produces 4 columns:
|Company|Year|Product|OrgUnit|Sales| they are ordered so that the OrgUnit selling the most of a product is showing first.
My goal - come up with a View that features
|Company|Year|Product|OrgUnit| - where I will have only 1 OrgUnit listed - one that sells the most of a product.

What I have tried so far is to create a MySql function in hopes that I can add a unique, auto-incremented ID to the view which will allow me to then group and pick the MAX/MIN id and deduce which row I should consider.

The function that I tried is:
CREATE DEFINER=`milos`@`%` FUNCTION `func_inc`() RETURNS int(11)
NO SQL
begin SET @var := IFNULL(@var,0) + 1; return @var; end

However, I can't or I don't know how to initialize the variable so that it always starts at 1, every time the View is run.

Anyway, in MS Access I would've grouped by 3 columns and picked First/Last on OrgUnit, but somehow this seemingly simple task is taking me too long on MySql. Hope someone can help me out.

Thank you!