fragment_downloaded_cb({"url":"tutorial.html#uris-urns-and-iris","fragment":"URIs, URNs and IRIs\nIn RDF data, everything that can be identified does so by\na URI. URIs uniquely identify an element in the RDF set, have\nproperties that are defined by URIs themselves, and point to\ndata that may either be other resources (identified by URI) or\nliteral values.\nGiven URIs are central to RDF data and SPARQL queries, there are\na number of ways to write, generalize and shorten them. URIs can\nof course be defined in their full form:\nSadly, not everything in the world can be trivially mapped to\na URI, as an aide Tracker offers helpers to generate URIs based\non UUIDv4 identifiers like tracker_sparql_get_uuid_urn,\nthese generated strings are typically called URNs.\nThe BASE keyword allows setting a common prefix for all URIs\nin the query:\nOr different prefixes can be defined with the PREFIX keyword:\nNotice how in the first triple, subject/predicate/object now look the\nsame? That is because they now all are prefixed names, here the rdf\nand rdfs prefixes are simply builtin.\nTaking the opposite path (i.e. expanding every term), this query could\nbe written as:\nFor the sake of familiarity, these elements have been referred to as\n\"URIs\", but these are actually IRIs, thus the unicode range is available:\n"});