DBIx::SearchBuilder::Unique - Ensure uniqueness of records in a collection

DBIx-SearchBuilder documentation Contained in the DBIx-SearchBuilder distribution.

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NAME

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DBIx::SearchBuilder::Unique - Ensure uniqueness of records in a collection

SYNOPSIS

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    package Foo::Collection;
    use base 'DBIx::SearchBuilder';

    use DBIx::SearchBuilder::Unique; # mixin

    my $collection = Foo::Collection->New();
    $collection->SetupComplicatedJoins;
    $collection->OrderByMagic;

    while (my $thing = $collection->Next) {
        # $thing is going to be distinct
    }

DESCRIPTION

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Currently, DBIx::SearchBuilder makes exceptions for databases which cannot handle both SELECT DISTINCT and ordering in the same statement; it drops the DISTINCT requirement. This, of course, means that you can get the same row twice, which you might not want. If that's the case, use this module as a mix-in, and it will provide you with an AddRecord method which ensures that a record will not appear twice in the same search.

AUTHOR

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Simon Cozens.

COPYRIGHT

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Copyright 2005 Best Practical Solutions, LLC

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

DBIx-SearchBuilder documentation Contained in the DBIx-SearchBuilder distribution. 
package DBIx::SearchBuilder::Unique;
use base 'Exporter';
our @EXPORT = qw(AddRecord);
our $VERSION = "0.01";
use strict;
use warnings;



sub AddRecord {
    my $self = shift;
    my $record = shift;

    # We're a mixin, so we can't override _CleanSlate, but if an object
    # gets reused, we need to clean ourselves out.  If there are no items,
    # we're clearly doing a new search
    $self->{"dbix_sb_unique_cache"} = {} unless (@{$self->{'items'}}[0]);
    return if $self->{"dbix_sb_unique_cache"}->{$record->id}++;
    push @{$self->{'items'}}, $record;
}

1;