DBIx::Class::Helper::ResultSet::OneRow(3pm)

NAME

DBIx::Class::Helper::ResultSet::OneRow - The first you always wanted

SYNOPSIS

 # note that this is normally a component for a ResultSet
 package MySchema::ResultSet::Person;
 use strict;
 use warnings;
 use parent 'DBIx::Class::ResultSet';
 __PACKAGE__->load_components('Helper::ResultSet::OneRow');
 sub person_named {
    $_[0]->search({ name => $_[1] })->one_row
 }

DESCRIPTION

This component codifies an alternate version of "first" in DBIx::Class::ResultSet. In practical use, "first" allows a user to do something like the following:

 my $rs = $schema->resultset('Foo')->search({ name => 'bar' });
 my $first = $rs->first;
 my @rest;
 while (my $row = $rs->next) {
    push @rest, $row
 }

Problematically, if you call "first" without the while loop afterwards and you got back more than one row, you are leaving a cursor open. Depending on your database this could increase memory usage or cause errors with later queries.

Fundamentally the difference is that when you use "one_row" you are guaranteed to exhaust the underlying cursor.

Generally speaking, unless you are doing something unusual, "one_row" is a good default.

METHODS

one_row($cond?)

Limits the ResultSet to a single row, and then returns the matching result object. In case no rows match, "undef" is returned as normal.

The optional $cond argument can be used like in search().

THANKS

Thanks to Aran Clary Deltac (BLUEFEET) for initially writing this module, and thanks to ZipRecruiter <https://www.ziprecruiter.com> for sponsoring that initial development.

AUTHOR

Arthur Axel "fREW" Schmidt <[email protected]>

COPYRIGHT AND LICENSE

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.