]> Querying 3 REDLAND Library Querying RDF query languages and execution. typedef librdf_query; typedef librdf_query_factory; void librdf_query_register_factory (librdf_world *world, const char *name, unsigned char *uri_string, void (*factory) (librdf_query_factory*)); librdf_query* librdf_new_query (librdf_world *world, const char *name, librdf_uri *uri, unsigned char *query_string, librdf_uri *base_uri); librdf_query* librdf_new_query_from_query (librdf_query *old_query); librdf_query* librdf_new_query_from_factory (librdf_world *world, librdf_query_factory *factory, const char *name, librdf_uri *uri, unsigned char *query_string, librdf_uri *base_uri); void librdf_free_query (librdf_query *query); librdf_query_results* librdf_query_execute (librdf_query *query, librdf_model *model); int librdf_query_get_limit (librdf_query *query); int librdf_query_set_limit (librdf_query *query, int limit); int librdf_query_get_offset (librdf_query *query); int librdf_query_set_offset (librdf_query *query, int offset); Provides classes to create query objects and to execute them over an RDF graph (librdf_model) returning a librdf_query_results Query result limits and offsets can be set. librdf_querytypedef struct librdf_query_s librdf_query; Redland query class. librdf_query_factorytypedef struct librdf_query_factory_s librdf_query_factory; Redland query factory class. librdf_query_register_factoryvoid librdf_query_register_factory (librdf_world *world, const char *name, unsigned char *uri_string, void (*factory) (librdf_query_factory*)); Register a query factory. world : redland world object name : the query language name uri_string : the query language URI string (or NULL if none) factory : pointer to function to call to register the factory librdf_new_querylibrdf_query* librdf_new_query (librdf_world *world, const char *name, librdf_uri *uri, unsigned char *query_string, librdf_uri *base_uri); Constructor - create a new librdf_query object. world : redland world object name : the name identifying the query language uri : the URI identifying the query language (or NULL) query_string : the query string base_uri : the base URI of the query string (or NULL) Returns : a new librdf_query object or NULL on failure librdf_new_query_from_querylibrdf_query* librdf_new_query_from_query (librdf_query *old_query); Should create a new query in the same context as the existing one as appropriate. old_query : the existing query librdf_query to use Returns : a new librdf_query object or NULL on failure librdf_new_query_from_factorylibrdf_query* librdf_new_query_from_factory (librdf_world *world, librdf_query_factory *factory, const char *name, librdf_uri *uri, unsigned char *query_string, librdf_uri *base_uri); Constructor - create a new librdf_query object. world : redland world object factory : the factory to use to construct the query name : query language name uri : query language URI (or NULL) query_string : the query string base_uri : base URI of the query string (or NULL) Returns : a new librdf_query object or NULL on failure librdf_free_queryvoid librdf_free_query (librdf_query *query); Destructor - destroy a librdf_query object. query : librdf_query object librdf_query_executelibrdf_query_results* librdf_query_execute (librdf_query *query, librdf_model *model); Run the query on a model. Runs the query against the (previously registered) model and returns a librdf_query_results for the result objects. query : librdf_query object model : model to operate query on Returns : librdf_query_results or NULL on failure librdf_query_get_limitint librdf_query_get_limit (librdf_query *query); Get the query-specified limit on results. This is the limit given in the query on the number of results allowed. query : librdf_query query object Returns : integer >=0 if a limit is given, otherwise <0 librdf_query_set_limitint librdf_query_set_limit (librdf_query *query, int limit); Set the query-specified limit on results. This is the limit given in the query on the number of results allowed. query : librdf_query query object limit : the limit on results, >=0 to set a limit, <0 to have no limit Returns : non-0 on failure librdf_query_get_offsetint librdf_query_get_offset (librdf_query *query); Get the query-specified offset on results. This is the offset given in the query on the number of results allowed. query : librdf_query query object Returns : integer >=0 if a offset is given, otherwise <0 librdf_query_set_offsetint librdf_query_set_offset (librdf_query *query, int offset); Set the query-specified offset on results. This is the offset given in the query on the number of results allowed. query : librdf_query query object offset : offset for results, >=0 to set an offset, <0 to have no offset Returns : non-0 on failure