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

[Wolfgang Laun]

You'll have to establish individual String objects to select type. There's
two ways to do that.

1. You know all possible type values and insert them as facts. This is the
most efficient way. (Perhaps wrap
the string into a fact type ItemType{ String type; }.)

rule  "StoreABC"

                when

                                #conditions

                                $type: String()

                                Number( $TotalSalesAmount : intValue,
intValue > 100)

                                from accumulate ( Sale(type == $type,
$amount : amount, $quantity : quantity)

                                from entry-point StoreABC,sum($amount *
$quantity))

                then

                                System.out.println("StoreABC sale exceeds
100…");

End

2. You can, e.g. by using some attribute order, select one Sale for each
type from a store.

rule  "StoreABC"

                when

                                #conditions

                               Sale( $pos: pos, $type: type )

                               not Sale( pos < pos, type == $type )

                               // same as before


HTH

-W


2011/1/3 Kiran Ananthpur Bacche (kbacche) <kbacche at cisco.com>

>  Hi,
>
>
>
> I have a event processing rule as follows
>
>
>
> declare Sale
>
>                 @role(event)
>
> end
>
>
>
> rule "StoreABC"
>
>
>
>                 when
>
>                                 #conditions
>
>                                 Number( $TotalSalesAmount : intValue,
> intValue > 100)
>
>                                 from accumulate ( Sale($amount : amount,
> $quantity : quantity)
>
>                                 from entry-point StoreABC,sum($amount *
> $quantity))
>
>                 then
>
>                                 System.out.println("StoreABC sale exceeds
> 100…");
>
> End
>
>
>
> The POJO Sale has a attribute “String type;”. The above rule actually
> ignores the type, and does the accumulation for all types put together. Now
> I want the rule to fire successfully only when the TotalSalesAmount for *_
> any_* given type exceeds 100.
>
>
>
> And is it possible to access the “type” of Sale whose sales exceeded 100,
> in the “Then” clause ?
>
>
>
> Example:
>
>
>
> Lets say the input events are  as below (Triplets – Type, Quantity and
> Amount)
>
>
>
> 1.       Apple , 10, 5
>
> 2.       Orange, 10, 6
>
> 3.       Banana,  20, 4
>
> 4.       Orange, 10, 5
>
> 5.       Apple, 2, 5
>
>
>
> Now in the above rule, the event fires after Event 2 since the total sales
> is > 100. However I want the rule to fire after Event 4 since at that point
> the sale of one particular item, viz. “Orange” exceeds 100 in this store. In
> the “THEN” clause of the rules, I also want access to a variable that
> indicates that it was “Orange” whose sale exceeded 100 in this store.
>
>
>
> Is this possible in Drools Fusion ? If yes, can you please let me know the
> changes to be made to the above rule ?
>
>
>
>
>
> Thanks
>
>   Kiran
>
>
>
>
>
> _______________________________________________
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> rules-users at lists.jboss.org
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>
>
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