An example of using optional subqueries with jQuery SPARQL

example-jquery-sparql-use.js

$.sparql("http://services.data.gov.uk/education/sparql")
 .prefix("sch-ont", "http://education.data.gov.uk/ontology/school#")
 .select(["?name", "?address1", "?address2", "?town", "?postcode"])
 .where("?school", "a", "sch-ont:School")
   .where("sch-ont:establishmentName", "?name")
   .where("sch-ont:districtAdministrative", "<http://education.data.gov.uk/placeholder-id/administrativeDistrict/City-of-London>;")
   .optional()
     .where("?school", "sch-ont:address", "?address")
     .where("?address", "sch-ont:address1", "?address1")
       .where("sch-ont:address2", "?address2")
       .where("sch-ont:postcode", "?postcode")
       .where("sch-ont:town", "?town")
   .end()
 .orderby("?name")
 .execute(cbfunc);