[rules-users] Does Drools Fusion support "Group By" clause ?

[Gabor Szokoli]

Hi,

2011/1/3 Kiran Ananthpur Bacche (kbacche) <kbacche at cisco.com>:
> I want the rule to fire successfully only when the TotalSalesAmount for
> _any_ given type exceeds 100.

I've never used "accumulate" myself, so I looked it up in the manual,
and there's an example that's exactly what you want :-)
(just substitute $order with your $type)

rule "Apply 10% discount to orders over US$ 100,00"
when
    $order : Order()
    $total : Number( doubleValue > 100 )
             from accumulate( OrderItem( order == $order, $value : value ),
                              sum( $value ) )
then
    # apply discount to $order
end

http://downloads.jboss.com/drools/docs/5.1.1.34858.FINAL/drools-expert/html_single/index.html#d0e4893



Gabor