[rules-users] Disting and group by

[Wolfgang Laun]

With an additional class PurchaseSum
    List<Customer> customers;
    ... purchaseDate;
    ... custNo;
    ... sum;
    }

you can write these rules;

rule "insert PurchaseSum"
when
  Customer( $pd : purchaseDate, $cn : custNo )
  not( PurchaseSum( purchaseDate == $pd, custNo == $cn ) )
then
  insert( new PurchaseSum( $cn, $pd );
end

rule "accumulate amounts"
when
  $cu : Customer( $pd : purchaseDate, $cn : custNo, $am : amount )
  $ps : PurchaseSum( purchaseDate == $pd, custNo == $cn, customers not
contains $cu )
then
  modify( $ps ){
     setSum( $ps.getSum() + amount ),
     setCustomers( $ps.getCustomers().add( $cu )
  }
end

rule "show amounts > X"
    salience -100
when
    $ps : PurchaseSum( amount > X )
thne
    System.out.println( $ps... );
    retract( $ps );
end

rule "clean up"
    salience -101
when
    $ps : PurchaseSum()
thne
    retract( $ps );
end

On 10 August 2010 20:03, vijrams <mailrvijay at gmail.com> wrote:
>
> Hi
>
> i have an object customer (purchaseDate, CustNo, Amount)
>
> i need to find the customers who purchased more than X amount in each date)
> ie group by customer then group by date and then sum of amount
>
>
> how do you write a rule for this
>
> thanks
> Vijay
> --
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