4 Replies Latest reply on Dec 5, 2012 12:47 AM by user571093

    no rows sleteced with SEM_RELATED function

    user571093
    user571093 Dec 4, 2012 1:05 AM
      hi,

      i am excersing the sem_related function sample code in oracle sem tech devloper's guide 11g.2;but got an issue i don't know what's going on in my code. the query is:

      SELECT diagnosis FROM patients
      WHERE SEM_RELATED(diagnosis,
      'rdfs:subClassOf', '<http://www.example.org/cancer/Immune_System_Disorder>', sem_models('cancer'), sem_rulebases('OWLPRIME'))= 1;

      but returned no rows for it. i created the table, the rdf table, sem_model, and entailment and inserted a couple of rows. the codes are follows:

      create table patients (id number, diagnosis varchar2 (40)) TABLESPACE rdf_tblspace;
      insert into patients values(1234, 'Rheumatoid_Arthritis');
      insert into patients values(2345, 'Immunodeficiency_Syndrome');
      insert into patients values(3456, 'AIDS');
      CREATE TABLE CANCER_RDF_DATA (ID NUMBER, TRIPLE SDO_RDF_TRIPLE_S) TABLESPACE rdf_tblspace;
      EXEC SEM_APIS.CREATE_SEM_MODEL('cancer', 'CANCER_RDF_DATA', 'TRIPLE');
      exec sem_apis.create_entailment('cancer_idx',sem_models('cancer'),sem_rulebases('owlprime')); (sometimes with 'SEM_APIS.REACH_CLOSURE,null,null')

      INSERT INTO cancer_rdf_data VALUES (1, sdo_rdf_triple_s('cancer', 'http://www.example.org/cancer/Immune_System_Disorder', 'http://www.w3.org/1999/02/22-rdf-syntax-ns#type', 'http://www.w3.org/2000/01/rdf-schema#Class'));
      INSERT INTO cancer_rdf_data VALUES (2, sdo_rdf_triple_s('cancer', 'http://www.example.org/cancer/Autoimmune_Disease', 'http://www.w3.org/1999/02/22-rdf-syntax-ns#type', 'http://www.w3.org/2000/01/rdf-schema#Class'));
      INSERT INTO cancer_rdf_data VALUES (3, sdo_rdf_triple_s('cancer', 'http://www.example.org/cancer/Rheumatoid_Arthritis', 'http://www.w3.org/1999/02/22-rdf-syntax-ns#type', 'http://www.w3.org/2000/01/rdf-schema#Class'));
      INSERT INTO cancer_rdf_data VALUES (4, sdo_rdf_triple_s('cancer', 'http://www.example.org/cancer/Immunodeficiency_Syndrome', 'http://www.w3.org/1999/02/22-rdf-syntax-ns#type', 'http://www.w3.org/2000/01/rdf-schema#Class'));
      INSERT INTO cancer_rdf_data VALUES (5, sdo_rdf_triple_s('cancer', 'http://www.example.org/cancer/T_Cell_Immunodeficiency', 'http://www.w3.org/1999/02/22-rdf-syntax-ns#type', 'http://www.w3.org/2000/01/rdf-schema#Class'));
      INSERT INTO cancer_rdf_data VALUES (6, sdo_rdf_triple_s('cancer', 'http://www.example.org/cancer/AIDS', 'http://www.w3.org/1999/02/22-rdf-syntax-ns#type', 'http://www.w3.org/2000/01/rdf-schema#Class'));
      INSERT INTO cancer_rdf_data VALUES (7, sdo_rdf_triple_s('cancer', 'http://www.example.org/cancer/Autoimmune_Disease', 'http://www.w3.org/2000/01/rdf-schema#subClassOf', 'http://www.example.org/cancer/Immune_System_Disorder'));
      INSERT INTO cancer_rdf_data VALUES (8, sdo_rdf_triple_s('cancer', 'http://www.example.org/cancer/Rheumatoid_Arthritis', 'http://www.w3.org/2000/01/rdf-schema#subClassOf', 'http://www.example.org/cancer/Autoimmune_Disease'));
      INSERT INTO cancer_rdf_data VALUES (9, sdo_rdf_triple_s('cancer', 'http://www.example.org/cancer/Immunodeficiency_Syndrome', 'http://www.w3.org/2000/01/rdf-schema#subClassOf', 'http://www.example.org/cancer/Immune_System_Disorder'));
      INSERT INTO cancer_rdf_data VALUES (10, sdo_rdf_triple_s('cancer', 'http://www.example.org/cancer/T_Cell_Immunodeficiency', 'http://www.w3.org/2000/01/rdf-schema#subClassOf', 'http://www.example.org/cancer/Immunodeficiency_Syndrome'));
      INSERT INTO cancer_rdf_data VALUES (11, sdo_rdf_triple_s('cancer', 'http://www.example.org/cancer/AIDS', 'http://www.w3.org/2000/01/rdf-schema#subClassOf', 'http://www.example.org/cancer/T_Cell_Immunodeficiency'));

      However the query above doesn't give me the expected results like in the tutorial. can anybody tell me what i am missing here. thanks in advance.

      kind regards,
      hong
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        • 1. Re: no rows sleteced with SEM_RELATED function
          alwu-Oracle
          alwu-Oracle Dec 4, 2012 8:29 PM (in response to user571093)
          Hi,

          The reason is that your table did not use URIs. However, you can try something like the following to construct URI on the fly:

          SELECT diagnosis FROM patients
          WHERE SEM_RELATED('<http://www.example.org/cancer/'||diagnosis||'>',
          'rdfs:subClassOf', '<http://www.example.org/cancer/Immune_System_Disorder>', sem_models('cancer'), sem_rulebases('OWLPRIME'))= 1;

          Let me know if it helps.

          Zhe Wu
          1 person found this helpful
          • 2. Re: no rows sleteced with SEM_RELATED function
            user571093
            user571093 Dec 4, 2012 11:30 PM (in response to alwu-Oracle)
            hi zhe,

            yes it works. thanks. however the following question is how can i perform the ontology assisted query using sem_related function without constructing the uri for the table column on the fly. do i need to create a semantic index that uses a URI prefix on that table column? i tried it once and it didn't work. or there is another way to do it? thanks in advance.

            kind regards
            hong
            • 3. Re: no rows sleteced with SEM_RELATED function
              alwu-Oracle
              alwu-Oracle Dec 5, 2012 12:02 AM (in response to user571093)
              Hi,

              Well, in your table, instead of using

              insert into patients values(1234, 'Rheumatoid_Arthritis');

              you can use something like

              insert into patients values(1234, '<http://www.example.org/cancer/Rheumatoid_Arthritis>');

              Alternatively, you can virtual column. For example,

              alter table patients add (diag_uri as ('<http://www.example.org/cancer/'||diagnosis||'>'));

              SELECT diagnosis FROM patients
              WHERE SEM_RELATED(diag_uri,
              'rdfs:subClassOf', '<http://www.example.org/cancer/Immune_System_Disorder>', sem_models('cancer'), sem_rulebases('OWLPRIME'))= 1;

              Thanks,

              Zhe Wu
              • 4. Re: no rows sleteced with SEM_RELATED function
                user571093
                user571093 Dec 5, 2012 12:47 AM (in response to alwu-Oracle)
                hi zhe,

                thanks for your quick reply. however adding uri to the existing databases will change the existing table structure and might affect the normal sql query. mayby it is a better way to construct the uri on the fly. another issure for sem_related function. the syntax of sem_related described in the guide is
                SEM_RELATED(
                sub VARCHAR2,
                predExpr VARCHAR2,
                obj VARCHAR2,
                ontologyName SEM_MODELS,
                ruleBases SEM_RULEBASES,
                index_status VARCHAR2,
                lower_bound INTEGER,
                upper_bound INTEGER ) RETURN INTEGER;

                i think it maybe missed the last parameter that is used for the primary invocation corresponding to sem_distance ancillary operator. so the complete one should be like this:
                SEM_RELATED(
                ...
                upper_bound INTEGER,
                the primary invocation) RETURN INTEGER;

                thanks.

                hong