David Portas wrote:

> Alternatively you can do the following using standard ANSI SQL, which should
> work on many different platforms:
>
> SELECT type
> FROM ord, product
> WHERE ord.id = product.id
> GROUP BY type
> HAVING SUM(units) >= ALL
> (SELECT DISTINCT SUM(units)
> FROM ord, product
> WHERE ord.id = product.id
> GROUP BY type);
>
> (untested)

This could return multiple values if there's a tie for most
common type.