NAME

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

SYNOPSIS

 use WQS::SPARQL;

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

METHODS

new

 my $obj = WQS::SPARQL->new;

Constructor.

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.

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

0.01

cpanm WQS::SPARQL

perl -MCPAN -e shell
install WQS::SPARQL