[rules-users] Call query from other query

[Mark Proctor]

did this work for you?

I'm hoping users can start to tell others how they are using backward
chaining, we need some successs "how to" stories out there, maybe a
tutorial or two :)

Mark

On Mon, Nov 28, 2011 at 10:48 PM, Mark Proctor <mproctor at codehaus.org>wrote:

> The query is treated just like a pattern. ? indicates whether the query
> should be materialised or not. In general if you aren't sure, then don't
> include the ? and let it materialise.
>
> The queries do not return any results, they are not functions. Like
> patterns the resuls are returned from out variable bindings in the
> parameters. The work in the same way that prolog predicates work, and you
> can find tuns of literatore on that.
>
> see  2.2.2.8 has a fair overview of this:
>
> http://docs.jboss.org/drools/release/5.3.0.Final/droolsjbpm-introduction-docs/html/releaseNotes.html#d0e50
>
> see 5.9 here:
>
> http://docs.jboss.org/drools/release/5.3.0.Final/drools-expert-docs/html/ch05.html#d0e6233
>
> This should work for your example:
> query query1(List $facts)
>    $facts := List() from collect( Fact( name == "name1" ) )
> end
>
> query query2
>    query1($l;)
> end
>
> The above $l should join with the results of query1, as it's unbound and
> thus an output variable.
>
> Mark
>
>
> On Mon, Nov 28, 2011 at 12:41 PM, Syargey <Syargey at tut.by> wrote:
>
>> I read in Drools guide, that queries can now call other queries.
>>
>> But the guide doesn't give much details, mostly paying attention to a
>> rather
>> specific case.
>>
>> I have two queries having common parts and try to figure out how to  get
>> rid
>> of duplicate code.
>>
>> Here is the simplified form of queries I'd like to have:
>> ---------
>>
>> query query1
>>    $facts: List()
>>        from collect( Fact( name == "name1" ) )
>> end
>>
>> query query2
>>    $l: List()
>>        from collect( Fact( value == "1" ) from ?query1() )
>> end
>>
>> ---------
>>
>> query2 syntax is invalid and and it is not clear for me how $facts from
>> query1 can be accessed in query2.
>>
>>
>> --
>> View this message in context:
>> http://drools.46999.n3.nabble.com/Call-query-from-other-query-tp3542082p3542082.html
>> Sent from the Drools: User forum mailing list archive at Nabble.com.
>> _______________________________________________
>> rules-users mailing list
>> rules-users at lists.jboss.org
>> https://lists.jboss.org/mailman/listinfo/rules-users
>>
>
>
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