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Run a SPARQL query

Source: R/vos_query.R
vos_query.Rd

Run a SPARQL query

Usage

vos_query(con, query)

Arguments

con

a ODBC connection to Virtuoso, from vos_connect()

query

a SPARQL query statement

Value

a data.frame containing the results of the query

Details

SPARQL is a graph query language similar in syntax SQL, but allows the use of variables to walk through graph nodes.

References

See also

vos_start(), vos_connect()

Examples

vos_status()
#> virtuoso isn't running.
# \donttest{
if(has_virtuoso()){
vos_start()
con <- vos_connect()

# show first 4 triples in the database
DBI::dbGetQuery(con, "SPARQL SELECT * WHERE { ?s ?p ?o } LIMIT 4")
}
#> Warning: Exiting, virtuoso template not found... is virtuoso installed?
#> PROCESS 'virtuoso-t', running, pid 2172.
#> Server is now starting up, this may take a few seconds...
#> virtuoso isn't running.
#> Error: nanodbc/nanodbc.cpp:1138: 00000
#> [OpenLink][Virtuoso iODBC Driver]CL033: Connect failed to localhost:1111 = localhost:1111. 
# }