[Dbix-class] A count() after a grouping select() produces a "Duplicate column" error

[Vladimir Melnik]

Hello!

Owing to Peter Rabbitson's kind help, we can now conclude that It occurs only when a ResultSet loads the Helper::ResultSet::AutoRemoveColumns component (see https://github.com/frioux/DBIx-Class-Helpers/issues/83).

In my specific case it's enough to load only the components I really need (e.g. Helper::ResultSet::SetOperations) instead of loading the whole Helper::ResultSet (which doesn't seem to be a good idea at all) to have my problem fixed.

Lots of thanks to all for the tips and clues!


On Tue, Oct 10, 2017 at 02:20:58PM +0300, Vladimir Melnik wrote:
> Dear colleagues,
> 
> Here's a little snippet of the code:
> 	$resultset
> 	    ->search(undef, { group_by => [ qw(quantity) ] })
> 	    ->count;
> 
> It produces the following exception:
> DBI Exception: DBD::mysql::st execute failed: Duplicate column name
> 'quantity' [for Statement "SELECT COUNT( * ) FROM (SELECT me.id,
> me.valid_from, me.valid_till, me.removed, me.provisioning_agreement_id,
> me.resource_piece_id, me.service_type_id, me.service_level_id,
> me.quantity, me.quantity FROM provisioning_obligation me GROUP BY
> quantity) me"] at
> /home/mmkeeper/perl5/perlbrew/perls/perl-5.24.0/lib/site_perl/5.24.0/DBIx/
> Class/Schema.pm line 1118.
> 
> What is the best way to avoid that?
> 
> Thanks in advance!
> 
> -- 
> V.Melnik
> 
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-- 
V.Melnik