The WSO2 Data Services Server supports exposing relational data in RDF (Resource Description Framework) format as a service. In the following example, we demonstrate how a CSV data source can be exposed as a RDF resource.
In order to expose relational data in RDF format, you need to configure the relevant data service query accordingly. To start, add a new query to your CSV data service. For instructions on creating a CSV data service, refer to section CSV.
1. Log on to the Data Services Server Management Console.
2. Click the Main menu and select List under Web Services.
3. The Deployed Services page appears which lists out all the currently active services and service groups.
Click on the data service you want to edit.
4. The dashboard of the data service opens. Click on the Edit Data Service link. In this example, we edit using the management console.
5. Navigate to the Queries page of the data service and click the Add New Query link.
6. The Add New Query page opens.
Since the output is a RDF result set, select output type as RDF from the drop-down list in the Output Mapping section.
RDF Base URI contains the format of rdf:about URI which uniquely identifies each resource. In this example, the RDF base URI is http://www.product/cd/
. This takes the value of column 1 of the CSV created here (which is the ProductCode) for each row and replaces it with the RDF about attribute inside rdf:Description element.
RDF Base URI :- http://www.product/cd/
Row namespace :- http://www.product/cd#