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DBIx::Class::Helper::ResultSet::OneRow(3pm) User Contributed Perl Documentation DBIx::Class::Helper::ResultSet::OneRow(3pm)


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


 # note that this is normally a component for a ResultSet
 package MySchema::ResultSet::Person;

 use strict;
 use warnings;

 use parent 'DBIx::Class::ResultSet';


 sub person_named {
    $_[0]->search({ name => $_[1] })->one_row


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.



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


Thanks to Aran Clary Deltac (BLUEFEET) for initially writing this module, and thanks to ZipRecruiter <> for sponsoring that initial developmentl


Arthur Axel "fREW" Schmidt <>


This software is copyright (c) 2020 by Arthur Axel "fREW" Schmidt.

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

2020-03-29 perl v5.30.0