[rules-users] Using from

[Marcus Ilgner]

Hi Aziz,

On Thu, Jul 17, 2008 at 8:26 PM, Aziz Boxwala <boxwala at yahoo.com> wrote:
> I have the following class structure.
>
> Class GrandFather {
>   List<Father> fathers;
>   public List<Father> getFathers() {return fathers;}
> }
>
> Class Father {
>    int age;
>   List<Son> sons;
>   public int getAge() {return age;}
>   public List<Son> getSons() {return sons;}
> }
>
> Class Son {
>  int age;
>   public int getAge() {return age;}
> }
>
> I'd like to write a rule that finds all the Fathers who have age > 45 and
> have Sons where the son's age is greater than 5. But I can't figure out how
> to use "from" to iterate over father first and then over son.
>
> Any help will be greatly appreciated.
>
> Thanks,
> --Aziz

Something like this?

rule "FatherAndSon
when
  $father : Father(age > 45)
  $son : Son(age > 5) from $father.sons
then
// do something
end

Best regards
Marcus