rdf - How to map relational database to OWL? -


i trying map relational database owl here 2 tables student(student_id,student_name,course_id)
course(course_id,course_name)

+----+--------+-----------+     | id | name   | course_id |   +----+--------+-----------+      |  1 | adam   |         5 |    |  2 | michael|         2 |     +----+--------+-----------+    +-----------+-------------+     | course_id | course_name |    +-----------+-------------+       |         2 | dm          |     |         5 | webir       |   +-----------+-------------+

now course_id foreign key in student table referencing course_id in course table.i created ontology(defined schema) using protege 4.3

i trying insert data owl file instances using jena api. in ontology, columns not foreign keys mapped datatype properties , foreign keys mapped object property per paper(mapping relational owl(section 4.4.4)). adding tuples instances student , course classes in jena. if foreign key object property how can use uniquely determine relation. here jena code have used add data instances owl file created in protege.

    (student std : studlist) {         individual stud = stud_ont.createindividual(nspace + "student/"                 + std.getstudent_id());         stud.addproperty(stud_id, std.getstudent_id());         stud.addproperty(stud_name, std.getstudent_name());         stud.addproperty(reln, std.getcourse_id());         printstream p = new printstream(                 "/home/owldm/newedu.owl");         m.writeall(p, "rdf/xml", null);         p.close();     }     (course crs : courselist) {          individual cour = course_ont.createindividual(nspace + "course/"                 + crs.getcourse_name());         cour.addproperty(course_course_name, crs.getcourse_name());         printstream p = new printstream(                 "/home/owldm/newedu.owl");         m.writeall(p, "rdf/xml", null);         p.close();     }

here "reln" object property(functional) adding course_id(values) foreign key. in relating 2 instances ,meaning suppose need infer "adam has taken webir course".

how can object property can replace foreign key value in relational uniquely join 2 tuples of 2 classes?
please suggest,any appreciated.

"the d2rq platform system accessing relational databases virtual, read-only rdf graphs".

you might want have @ that


Comments

Post a Comment

Popular posts from this blog

android - Get AccessToken using signpost OAuth without opening a browser (Two legged Oauth) -

i using signpost oauth access data magento server. have read various tutorials on same , reach point open browser user can enter credentials. however, per requirement have automate part. hence, user should not browser page. have set-up done on server side ( magento ), hit url , returned call page. same through program in android. i have tried below, consumer = new commonshttpoauthconsumer(key, secret); provider = new commonshttpoauthprovider(oauth_init_url,access_token_url, authorize_url); try { provider.retrieverequesttoken(consumer, oauth.out_of_band); log.d("tokens" , consumer.gettoken() + " -- " + consumer.gettokensecret()); } and request tokens. dont know how bypass next step. tried directly accessing accesstoken (stupid of me) provider.retrieveaccesstoken(consumer, "mycallback://callback"); no luck, ends in oauth.signpost.exception.oauthnotauthorizedexception: authorization failed (server replied 401). ...
Read more

org.mockito.exceptions.misusing.InvalidUseOfMatchersException: mockito -

getting error org.mockito.exceptions.misusing.invaliduseofmatchersexception: invalid use of argument matchers! 1 matchers expected, 2 recorded. exception may occur if matchers combined raw values: //incorrect: somemethod(anyobject(), "raw string"); when using matchers, arguments have provided matchers. example: //correct: somemethod(anyobject(), eq("string matcher")); at when( getprogramservice .callservice(any(getprogramtype.class))) .thenreturn(jaxbresponse); please explain error , possible resolution the code posted looks fine; don't see problem it. code before or above causing exception. key here: invalid use of argument matchers! 1 matchers expected, 2 recorded. any , used above, doesn't return "special kind of null" or "special kind of getprogramtype"; don't exist. instead, returns null , side effect puts matcher on stack. whe...
Read more

google shop client API returns 400 bad request error while adding an item -

i'm working on solution add items in google shopping market java application. following tutorial real mess because of missing classes of laste release, after setting 1.5-beta maven managed make base example typecheck correctly classes. still can make simple task of adding 1 item. instead of posting whole code i'm posting part creates product feed. private product createproduct(string id) { product product = new product(); product.title = "red wool sweater"; product.content = new content( "text", "comfortable , soft, sweater keep warm on " + "cold winter nights. red , blue stripes."); product.appcontrol = new appcontrol(); product.appcontrol.addrequireddestination("productads"); product.externalid = id; product.lang = "it"; product.country = "it"; product.condition = "nuovo"; product.price = new price("eu...
Read more