Customizing the Virtuoso SPARQL Endpoint

This page will guide you through changing the SPARQL endpoint web page. You can create different variants of the page for different IRIs:

1. The default SPARQL endpoint page is found in the procedure named WS.WS."/!sparql/", which is built from source code found in libsrc/Wi/sparql_io.sql.
2. Copy the code from the above procedure, and load it to a different name, e.g., WS.WS."/!sparql_new/", through iSQL --
   

   
   SQL> CREATE PROCEDURE WS.WS."/!sparql_new/"
     ( INOUT path VARCHAR, 
       INOUT params ANY, 
       INOUT lines ANY
     )
     {...
       http('  <p>TEST This query page is designed to help you test OpenLink Virtuoso</p>
     ...
     };
   Done. -- 60 msec.
   SQL>
   

   
   
3. Remove the VHost definition targeting the original page --
   

   
   SQL> DB.DBA.VHOST_REMOVE (lpath=>'/sparql');
   

   
   
4. Add a VHost definition targeting your new page. The command follows this form --
   

   
   SQL> DB.DBA.VHOST_DEFINE 
          ( lpath=>'/sparql/', 
            ppath => '/your-function-name/', 
            is_dav => 1, 
            vsp_user => 'dba', 
            opts => vector('noinherit', 1)
          );
   

   
   -- so, for this example --
   

   
   SQL> DB.DBA.VHOST_DEFINE 
          ( lpath=>'/sparql/', 
            ppath => '/!sparql_new/', 
            is_dav => 1, 
            vsp_user => 'dba', 
            opts => vector('noinherit', 1)
          );
   

   
   
5. Give the SPARQL user permission to execute your new page, following this form --
   

   
   SQL> GRANT EXECUTE 
          ON WS.WS."your-function" 
          TO "SPARQL"
        ;
   

   
   -- so, for this example --
   

   
   SQL> GRANT EXECUTE
          ON WS.WS."/!sparql_new/"
          TO "SPARQL"
        ;
   

   
   Note: you should use double quotes around name of "SPARQL" user and the upper case, to avoid confusion with the SPARQL keyword, you should always use double-quote wrappers and upper-case to refer to the "SPARQL" user.
   
   
6. Set attributes on your new page, such that Virtuoso's HTTP server component will not treat it as a physical path (DAV or filesystem) to be read and compiled as a procedure, following the command form --
   

   
   SQL> registry_set 
          ( '/your-function-name/', 
            'no_vsp_recompile'
          );
   

   
   -- so, for this example --
   

   
   SQL> registry_set
          ( '/!sparql_new/', 
            'no_vsp_recompile'
          );
   

   
   
7. Access the new SPARQL endpoint, which should show your changes --
   
   
   
   

CategorySPARQL CategoryVirtuoso