fragment_downloaded_cb({"url":"tutorial.html#blank-nodes","fragment":"Blank nodes\nBlank nodes (or anonymous nodes) are nodes without an specified URI, these\nare given a query-local name via the special _: prefix:\nNote that running this query multiple times will insert a different blank\nnode each time. Unlike e.g.:\nWhere any second insert would be redundantly attempting to add the same\ntriple to the store.\nBy default, Tracker deviates from the SPARQL standard in the handling\nof blank nodes, these are considered a generator of URIs. The\nTRACKER_SPARQL_CONNECTION_FLAGS_ANONYMOUS_BNODES flag may be used to\nmake Tracker honor the SPARQL 1.1 standard with those. The standard\ndefines blank nodes as truly anonymous, you can only use them to determine\nthat there is something that matches the graph pattern you defined. The\npractical difference could be seen with this query:\nTracker by default will provide you with URNs that can be fed into other\nSPARQL queries as URIs. With TRACKER_SPARQL_CONNECTION_FLAGS_ANONYMOUS_BNODES\nenabled, the returned elements will be temporary names that can only be used to\ndetermine the existence of a distinct match. There, blank nodes can match named\nnodes, but named nodes do not match with blank nodes.\nThis nature of blank nodes is however useful to query for elements whose\nresource URI is irrelevant, e.g.:\nIn this query there is no interest in getting the intermediate album\nand artist resources, so blank nodes can be used for them.\nBlank nodes have an in-place [ ] syntax, which declares a distinct\nempty blank node, it can also contain predicate/object pairs to further\ndefine the structure of the blank node. E.g. the previous query could\nbe rewritten like:\n"});