Data Graphs

Data Graphs — RDF graph sources for triples.

Synopsis

                    rasqal_data_graph;
rasqal_data_graph*  rasqal_new_data_graph               (raptor_uri *uri,
                                                         raptor_uri *name_uri,
                                                         int flags);
void                rasqal_free_data_graph              (rasqal_data_graph *dg);
enum                rasqal_data_graph_flags;
void                rasqal_data_graph_print             (rasqal_data_graph *dg,
                                                         FILE *fh);

Description

Data graphs are used in the query to describe RDF graphs that can be used to query against. The graphs can be used either with raptor_uri to name the graph, or without a name. The query language determines which graphs are used in the query.

Details

rasqal_data_graph

typedef struct {
  raptor_uri* uri;
  raptor_uri* name_uri;
  int flags;
} rasqal_data_graph;

A source of RDF data for querying.

The uri is the original source (base URI) of the content. It may also have an additional name name_uri as long as flags is RASQAL_DATA_NAMED

raptor_uri *uri;

source URI

raptor_uri *name_uri;

name of graph for RASQAL_DATA_NAMED

int flags;

RASQAL_DATA_GRAPH_NAMED or RASQAL_DATA_GRAPH_BACKGROUND

rasqal_new_data_graph ()

rasqal_data_graph*  rasqal_new_data_graph               (raptor_uri *uri,
                                                         raptor_uri *name_uri,
                                                         int flags);

Constructor - create a new rasqal_data_graph.

The name_uri is only used when the flags are RASQAL_DATA_GRAPH_NAMED.

uri :

source URI

name_uri :

name of graph (or NULL)

flags :

RASQAL_DATA_GRAPH_NAMED or RASQAL_DATA_GRAPH_BACKGROUND

Returns :

a new rasqal_data_graph or NULL on failure.

rasqal_free_data_graph ()

void                rasqal_free_data_graph              (rasqal_data_graph *dg);

Destructor - destroy a rasqal_data_graph object.

dg :

rasqal_data_graph object

enum rasqal_data_graph_flags

typedef enum {
  RASQAL_DATA_GRAPH_NONE  = 0,
  RASQAL_DATA_GRAPH_NAMED = 1,
  RASQAL_DATA_GRAPH_BACKGROUND = 2,
} rasqal_data_graph_flags;

Flags for the type of rasqal_data_graph.

These are used by rasqal_query_add_data_graph(). See rasqal_data_graph.

RASQAL_DATA_GRAPH_NONE

Internal.

RASQAL_DATA_GRAPH_NAMED

Graphs with a source and name.

RASQAL_DATA_GRAPH_BACKGROUND

Graphs with a source only.

rasqal_data_graph_print ()

void                rasqal_data_graph_print             (rasqal_data_graph *dg,
                                                         FILE *fh);

Print a Rasqal data graph in a debug format.

The print debug format may change in any release.

dg :

rasqal_data_graph object

fh :

the FILE* handle to print to