[Dbix-class] Column aliases and the ambiguity of 'as'

[Andrew Bramble]

Hello All,

I'm still playing around with DBIC but lovin it. 
As pointed out to me today (thanks castaway) in #dbix-class , the 'as' 
attributes to a resultset search have no bearing on the query used , only on 
the returned objects which are give an accessor method described by the 'as' 
attribute. I kicked myself when going back to read the BIG hint in the 
ResultSet docs that say 'it will fail miserably' when used in this way. 
Frustrating because the below search would be just great except for the fact 
that the select columns cannot possible be referred to in the 'having' 
clause. I had a crack at resolving this myself today in 
DBIx::Class::Storage::DBI but it all fell down in _recurse_fields 

the select produced by the below search looks like
SELECT id , IFNULL(MIN(rights.permit,0)), 
IFNULL(MIN(inherited_rights.permit,0)) FROM ......

When it would be preferred to have 
SELECT id AS id, IFNULL(MIN(rights.permit,0)) AS explicit_allow   .. .etc

I realise it is late and am starting to babble. 
Would this type of behaviour be useful to anyone else ? 

my $m= $s->resultset('Meta')->search( undef,
    {
            join=>[ qw/rights inherited_rights/ ],
            select=>[
                'id',
                { ifnull=>[ {min=>'rights.permit' },,0 ] } ,
                { ifnull=>[ {min=>'inherited_rights.permit'}, 0 ]  },
            ],
            as => [
                'id', 'explicit_allow', 'inherited_allow'
            ],
            order_by=>'explicit_allow',
            group_by=>[qw/me.id/],
            having=>{
                 explicit_allow=>1,
             }
    }
);

Many thanks for a great ORM

AB