NAME

WQS::SPARQL::Query::Select - Simple SPARQL select query.

SYNOPSIS

 use WQS::SPARQL::Query::Select;

 my $obj = WQS::SPARQL::Query::Select->new;
 my $sparql = $obj->select_value($property_pairs_hr);

METHODS

new

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

Constructor.

Returns instance of class.

select_value

 my $sparql = $obj->select_value($property_pairs_hr);

Construct SPARQL command and return it. Input is reference to hash with pairs property => value.

Value could be in forms:

• Q__number__

  QID identifier.

  Example output: Q42

• __string__@__lang__

  String with language.

  'lang' is 2 character language code.

  Example output: 'string'@en

• __string__

  String without language.

  Example output: 'string'

Returns string.

ERRORS

 new():
         From Class::Utils::set_params():
                 Unknown parameter '%s'.

 select_value():
         Bad property '%s'.

EXAMPLE

 use strict;
 use warnings;

 use WQS::SPARQL::Query::Select;

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

 my $property = 'P957';
 my $isbn = '80-239-7791-1';
 my $sparql = $obj->select_value({$property => $isbn});

 print "Property: $property\n";
 print "ISBN: $isbn\n";
 print "SPARQL:\n";
 print $sparql;

 # Output:
 # Property: P957
 # ISBN: 80-239-7791-1
 # SPARQL:
 # SELECT ?item WHERE {
 #   ?item wdt:P957 '80-239-7791-1'.
 # }

DEPENDENCIES

Class::Utils, Error::Pure.

SEE ALSO

WQS::SPARQL::Query

Useful Wikdata Query Service SPARQL queries.

WQS::SPARQL::Query::Count

Simple SPARQL count query.

REPOSITORY

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

AUTHOR

Michal Josef Špaček mailto:skim@cpan.org

http://skim.cz

LICENSE AND COPYRIGHT

© 2020-2023 Michal Josef Špaček

BSD 2-Clause License

VERSION

0.01

cpanm WQS::SPARQL::Query

perl -MCPAN -e shell
install WQS::SPARQL::Query