You don't know what exactly?
> Hello Lorenz, kindly if you can suggest me how to avoid this situation.
> Recent data property value can be achieved using Jena but I dont know how
> to do it in this case because Student is a class here.
>
> On Sat, Nov 12, 2016 at 4:55 PM, Lorenz B. <
> buehm...@informatik.uni-leipzig.de> wrote:
>
>> And what is the question now?
>>
>> By the way, those rules do not overwrite any value, the logic is
>> supposed to be monotonic, i.e. only additional triples are inferred.
>> Replacement has to be done in the application code.
>>
>>> The students have to appear multiple time in the exam. When student
>> appears
>>> first time, he scored 80% and got in the category of Excellent Students
>>> list. Second time he appears, he scored 60% and thus appeared in Average
>>> Student.
>>> Now after two exams, the Student in the owl file should be in the Average
>>> Student list but both Excellent and Average Student appears and thus the
>>> first value of first exam also there.
>>>
>>> On Sun, Oct 16, 2016 at 9:16 PM, Dave Reynolds <
>> dave.e.reyno...@gmail.com>
>>> wrote:
>>>
>>>> On 14/10/16 14:53, javed khan wrote:
>>>>
>>>>> I have divided Students into ExcellentStudents and AverageStudents
>> based
>>>>> on
>>>>> some criteria via Jena rules: if student got 75% or more, he/she will
>> be
>>>>> in
>>>>> "ExcellentStudents" else "AverageStudents".
>>>>> In first exam, if some one takes 75% and put into ExcellentStudents
>> but
>>>>> next time if he scores less than 75%, he will be AverageStudents.
>>>>>
>>>>> The problem is that when I store it in the file, the previous value
>> does
>>>>> not overwrite the new one and I see both categories in the owl file
>> like:
>>>>> John
>>>>> AverageStudents
>>>>> ExcellentStudents
>>>>>
>>>>> How can we cope with this issue?
>>>>>
>>>> If in your data there is only ever one exam result for a given student
>>>> then you it might make sense to have AverageStudents/ExcellentStudent
>>>> classes. However, if you have multiple exam results in the same data
>> then
>>>> naturally some will be average on some and excellent on others.
>>>>
>>>> So you have to decide what your semantics are. Do you want
>>>> ExcellentStudent to mean that the student averages 75% or more across
>> all
>>>> exams? Or you you want an n-relationship between students, exams and
>>>> classifications?
>>>>
>>>> Once you've decided what you semantics are and how the answers should
>> look
>>>> then you can figure out an implementation.
>>>>
>>>> Dave
>>>>
>>>>
>>>>
>>>>> The rules are:
>>>>>
>>>>> String rule = "[rule1:(?x http://www.w3.org/1999/02/22-
>> rdf-syntax-ns#type
>>>>> http://www.semanticweb.org#Student) "
>>>>> + "( ?x http://www.semanticweb.org#score ?marks )"
>>>>> + "greaterThan(?marks, 70) "
>>>>> + " -> (?x http://www.w3.org/1999/02/22-r
>>>>> df-syntax-ns#type
>>>>> http://www.semanticweb.org#ExcellentStudents )]"
>>>>>
>>>>> + "[rule2:(?x http://www.w3.org/1999/02/22-rdf-syntax-ns#type
>>>>> http://www.semanticweb.org#Student) "
>>>>> + "( ?x http://www.semanticweb.org#score ?marks )"
>>>>> + "lessThan(?marks, 70) "
>>>>> + " -> (?x http://www.w3.org/1999/02/22-r
>>>>> df-syntax-ns#type
>>>>> http://www.semanticweb.org#AverageStudents )]";
>>>>>
>>>>>
>>>>> for (Iterator i = inf.listResourcesWithProperty(RDF.type,stutype1 );
>>>>> i.hasNext();) {
>>>>> inf.listStatements(null,RDF.type, "ExcellentStudents");
>>>>>
>>>>> }
>>>>> for (Iterator i = inf.listResourcesWithProperty(RDF.type,
>> stutype2);
>>>>> i.hasNext();) {
>>>>> inf.listStatements(null,RDF.type, "AverageStudents");
>>>>>
>>>>> }
>>>>>
>>>>> I also tried with SPARQL but same result.
>>>>> SELECT * " +
>>>>> " WHERE { ?x rdf:type std:ExcellentStudents . ?x
>>>>> rdf:type
>>>>> std:AverageStudents}";
>>>>>
>>>>>
>> --
>> Lorenz Bühmann
>> AKSW group, University of Leipzig
>> Group: http://aksw.org - semantic web research center
>>
>>
--
Lorenz Bühmann
AKSW group, University of Leipzig
Group: http://aksw.org - semantic web research center
