/ 
WQS-SPARQL-0.02
River stage one • 1 direct dependent • 1 total dependent
/ WQS::SPARQL

NAME

WQS::SPARQL - Simple SPARQL query for Wikidata Query Service.

SYNOPSIS

use WQS::SPARQL;

my $obj = WQS::SPARQL->new(%params);
my $ret_hr = $obj->query($sparql);
my $count = $obj->query_count($sparql_count);

METHODS

new

my $obj = WQS::SPARQL->new(%params);

Constructor.

  • agent

    User agent.

    Default value is 'WQS::SPARQL (__VERSION__)'.

  • lwp_user_agent

    LWP::UserAgent object.

    Default value is instance of LWP::UserAgent with constructor 'agent' parameter.

  • query_site

    Query site.

    Default value is 'query.wikidata.org'.

  • sparql_endpoint

    SPARQL endpoint.

    Default value is '/bigdata/namespace/wdq/sparql'.

  • verbose

    Verbose mode.

    Default value is 0.

Returns instance of class.

query

my $ret_hr = $obj->query($sparql);

Do SPARQL query and returns result.

Returns reference to hash with result.

query_count

my $count = $obj->query_count($sparql_count);

Get count value for $sparql_count SPARQL query.

Returns number.

ERRORS

new():
        From Class::Utils::set_params():
                Unknown parameter '%s'.
        Parameter 'lwp_user_agent' must be a 'LWP::UserAgent' instance.

EXAMPLE1

use strict;
use warnings;

use Data::Printer;
use WQS::SPARQL;
use WQS::SPARQL::Query::Count;

if (@ARGV < 1) {
        print STDERR "Usage: $0 ccnb\n";
        exit 1;
}
my $ccnb = $ARGV[0];

my $q = WQS::SPARQL->new;
my $sparql = WQS::SPARQL::Query::Count->new->count_simple('P3184',
        $ccnb);
my $ret_hr = $q->query($sparql);

# Dump structure to output.
p $ret_hr;

# Output for cnb002826100:
# \ {
#     head      {
#         vars   [
#             [0] "count"
#         ]
#     },
#     results   {
#         bindings   [
#             [0] {
#                 count   {
#                     datatype   "http://www.w3.org/2001/XMLSchema#integer",
#                     type       "literal",
#                     value      1
#                 }
#             }
#         ]
#     }
# }

EXAMPLE2

use strict;
use warnings;

use WQS::SPARQL;
use WQS::SPARQL::Query::Count;

if (@ARGV < 1) {
        print STDERR "Usage: $0 ccnb\n";
        exit 1;
}
my $ccnb = $ARGV[0];

my $q = WQS::SPARQL->new;
my $sparql = WQS::SPARQL::Query::Count->new->count_simple('P3184',
        $ccnb);
my $ret = $q->query_count($sparql);

# Print count.
print "Count: $ret\n";

# Output for 'cnb002826100':
# Count: 1

# Output for 'bad':
# Count: 0

DEPENDENCIES

Class::Utils, Error::Pure. HTTP::Request, JSON::XS, LWP::UserAgent, URI, URI::QueryParam, Unicode::UTF8.

SEE ALSO

WQS::SPARQL::Query

Usefull Wikdata Query Service SPARQL queries.

REPOSITORY

https://github.com/michal-josef-spacek/WQS-SPARQL

AUTHOR

Michal Josef Špaček mailto:skim@cpan.org

http://skim.cz

LICENSE AND COPYRIGHT

© Michal Josef Špaček 2020-2023

BSD 2-Clause License

VERSION

0.02