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Re: Sparql advanced question on for all and at least assertion on property...

From: Lee Feigenbaum <lee@thefigtrees.net>
Date: Tue, 21 Dec 2010 05:08:40 -0500
Message-ID: <4D107CA8.7030902@thefigtrees.net>
To: Andy Seaborne <andy.seaborne@epimorphics.com>
CC: Matteo Busanelli <mbusanelli@imolinfo.it>, public-sparql-dev@w3.org
I think you can also do this in SPARQL 1.0 with the OPTIONAL clause, 
since OPTIONAL is "greedy" (will bind if it can).


SELECT ?person
WHERE {
   ?person a ex:Person .
   OPTIONAL {
     ?person :has_number ?number.
     FILTER(?number > 10)
   }
   FILTER(!bound(?number)) # keep those that couldn't match the opt.
}

This is untested and it's 5am, so I may be missing something obvious :-)

Lee

On 12/21/2010 3:47 AM, Andy Seaborne wrote:
> In SPARQL 1.1, there is grouping and MAX:
>
> SELECT ?person
> WHERE {
> ?person :has_number ?number .
> }
> GROUP BY ?person
> HAVING (MAX(?number) < 10)
>
> Andy
>
> On 20/12/10 14:53, Matteo Busanelli wrote:
>> I everyone sparql people,
>> i need support on a query that is giving me trouble.
>>
>> I want to select all instances of a class witch have ALL the value of
>> the property P1 matching a condition.
>> My problem is to express the ALL assertion. I'm able of selecting all
>> the triple in witch an instance verify the condition for the property P1
>> but I can't assert that this istance doesen't have also a valorization
>> of the property that doesn't verify my condition.
>>
>> EXAMPLE
>> Having:
>>
>> Matteo has_number 12
>> Matteo has_number 3
>> Matteo has_number 8
>>
>> Lee has_number 9
>> Lee has_number 2
>> Lee has_number 4
>>
>> I want to find the persons that HAS ONLY number less than 10.
>>
>> This doesn't work because return also Matteo:
>>
>> SELECT DISTINCT ?person
>> WHERE {
>> ?person :has_number ?number .
>> FILTER (?number < 10)
>> }
>>
>> Result:
>>
>> Matteo
>> Lee
>>
>> Wanted result:
>> Lee
>>
>> Can you suggest me the way I can do that?
>>
>> Thank you for your time,
>> Matteo
>>
>>
>
>
Received on Tuesday, 21 December 2010 10:09:25 GMT

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