[Dbix-class] can we store the DBIx::Class into cache system?
Hi, all, I have a question about the how to save the DBIx::Class object into cache system, example: we use CHI, my question is: just save DBIx::Class into Cache system like other data type? I mean just like array, hash, scalar? don't need do other things? so, the DBIx::Class will be lost database connection and lost data? thanks Mike.G ___ List: http://lists.scsys.co.uk/cgi-bin/mailman/listinfo/dbix-class IRC: irc.perl.org#dbix-class SVN: http://dev.catalyst.perl.org/repos/bast/DBIx-Class/ Searchable Archive: http://www.grokbase.com/group/dbix-class@lists.scsys.co.uk
RE: [Dbix-class] Unknown column in 'group statement'
Hi Peter,
-Original Message-
From: Peter Rabbitson [mailto:rabbit+d...@rabbit.us]
Sent: 23 July 2009 22:45
To: DBIx::Class user and developer list
Subject: Re: [Dbix-class] Unknown column in 'group statement'
On Thu, Jul 23, 2009 at 04:19:01PM +0100, Anthony Gladdish wrote:
Hi,
Using:
Perl 5.10.
DBIC 0.08108.
1. My result source tables with relationships are:
Event.pm:
__PACKAGE__-set_primary_key('id');
__PACKAGE__-belongs_to( 'leader' = 'Trainer' ) ;
__PACKAGE__-has_many( 'assistingtrainers' = 'AssistingTrainer', 'event' );
__PACKAGE__-many_to_many('assistants' = 'assistingtrainers', 'trainers' );
AssistingTrainer.pm:
__PACKAGE__-set_primary_key('event','trainer');
__PACKAGE__-belongs_to( 'events' = 'Event', 'event' );
__PACKAGE__-belongs_to( 'trainers' = 'Trainer', 'trainer' );
Trainer.pm:
__PACKAGE__-set_primary_key('id');
2. My ResultSet::Event.pm methods:
sub goEvents {
my $self = shift;
my $where = {};
$where-{status} = { '' = 2 };
return $self-search($where);
}
sub events_during_lookback_period {
my $self = shift;
my $default_lookback_period = DateTime::Duration-new( years = 3 );
my $lookback_period = shift || $default_lookback_period;
my $earliest_date = DateTime-now() - $lookback_period;
return $self-goEvents()-search_rs(
{
-and = [
start = { '', DateTime-now() },
start = { '', $earliest_date },
],
}
);
}
sub distinct_assistants {
my $self = shift;
my $assistants = [];
my $rs = $self-search_rs(
undef,
{
columns = [ qw/me.id/ ],
distinct = 1,
prefetch = [ { 'assistingtrainers' = 'trainers' } ],
join = [ { 'assistingtrainers' = 'trainers' } ],
},
);
while ( my $e = $rs-next() ) {
foreach my $at ( $e-assistingtrainers() ) {
push( @$assistants, $at-trainers );
}
}
return $assistants;
}
This is a design lapse - we married distinct with group_by too early
in the code and what you are seeing is the fallout (i.e. distinct
applies to all columns not just the ones you are trying to select).
I will have to discuss this with the rest of the developers before
we solve it, but for the time being simply change
distinct = 1
to
group_by = [ qw/me.id/ ]
The prefetch will keep working as expected.
Cheers
This works, but only if I omit columns = too, i.e.:
{
group_by = [ qw/me.id/ ],
prefetch = [ { 'assistingtrainers' = 'trainers' } ],
join = [ { 'assistingtrainers' = 'trainers' } ],
},
I'm assuming this is ok, although I would have thought columns and group_by
would be needed together (correct me if I'm wrong), and doing this:
{
columns = [ qw/me.id/ ],
group_by = [ qw/me.id/ ],
prefetch = [ { 'assistingtrainers' = 'trainers' } ],
join = [ { 'assistingtrainers' = 'trainers' } ],
},
... produces error:
DBIx::Class::ResultSet::next(): DBI Exception: DBD::mysql::st execute failed:
Unknown column 'start' in 'where clause' [for Statement SELECT me.id,
assistingtrainers.event, assistingtrainers.trainer, trainers.id, trainers.name,
trainers.email, trainers.phone, trainers.initials, trainers.loginId,
trainers.password FROM (SELECT me.id FROM event me WHERE ( ( ( start ? AND
start ? ) AND status ? ) ) GROUP BY me.id) me LEFT JOIN trainer_assist
assistingtrainers ON assistingtrainers.event = me.id LEFT JOIN trainer trainers
ON trainers.id = assistingtrainers.trainer WHERE ( ( ( start ? AND start ?
) AND status ? ) ) ORDER BY assistingtrainers.event with ParamValues:
0='2009-07-24T09:46:14', 1='2006-07-24T09:46:14', 2=2, 3='2009-07-24T09:46:14',
4='2006-07-24T09:46:14', 5=2]
Thanks for your help,
Anthony
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Re: [Dbix-class] Relations for multi-class object inflation from one table
On Thu, Jul 23, 2009 at 4:12 PM, Oleg Kostyukcub.ua...@gmail.com wrote:
Hello all,
I read about Dynamic Sub-classing DBIx::Class proxy classes in
DBIx::Class::Manual::Cookbook, and have question.
package My::Schema::Result::Company;
use base qw/DBIx::Class/;
__PACKAGE__-load_components(qw/Core/);
__PACKAGE__-table('companies');
__PACKAGE__-add_columns(qw/company_id ../);
__PACKAGE__-set_primary_key('company_id');
__PACKAGE__-has_many('admins', 'My::Schema::Result::User::Admin', );
__PACKAGE__-has_many('users', 'My::Schema::Result::User', );
__PACKAGE__-has_many('all_users', 'My::Schema::Result::User', );
My questions is:
1) what should be instead of '' in has_many() calls above? I
think, this should be something like this (for first has_many): {
'foreign.company_id' = 'self.company_id', 'foreign.admin' = 1 } - is
this correct?
You can't define rels using constants in FK definitions like
'foreign.admin' = 1. You have to define just the 'all_users' rel with
{ 'foreign.company_id' = 'self.company_id' } and create result class
methods for 'users' and 'admins' like:
sub users_rs {
my $self = shift;
return $self-all_users_rs({ admin = '0' });
}
sub users {
my $self = shift;
my $rs = $self-users_rs;
return wantarray ? $rs-all : $rs;
}
sub admins_rs {
my $self = shift;
return $self-all_users_rs({ admin = '1' });
}
sub admins {
my $self = shift;
my $rs = $self-admins_rs;
return wantarray ? $rs-all : $rs;
}
Or you can create a base result class called Person, then Admin and
User classes as a views (CREATE VIEW) over Person, thus you can define
the rels like:
__PACKAGE__-has_many('admins', 'My::Schema::Result::User::Admin',
{ 'foreign.company_id' = 'self.company_id' });
__PACKAGE__-has_many('users', 'My::Schema::Result::User',
{ 'foreign.company_id' = 'self.company_id' });
__PACKAGE__-has_many('all_users', 'My::Schema::Result::Person',
{ 'foreign.company_id' = 'self.company_id' });
3) do I need write belongs_to(company) in User::Admin too, or only in
User will be enough?
Just in User should be enough.
--
wallace reis/wreis Catalyst and DBIx::Class consultancy with a clue
Software Developer and a commit bit:
http://shadowcat.co.uk/catalyst/
Shadowcat Systems Limited
http://www.shadowcat.co.uk http://www.linkedin.com/in/wallacereis
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Re: [Dbix-class] Unknown column in 'group statement'
On Fri, Jul 24, 2009 at 11:00:50AM +0100, Anthony Gladdish wrote:
Hi Peter,
-Original Message-
From: Peter Rabbitson [mailto:rabbit+d...@rabbit.us]
Sent: 23 July 2009 22:45
To: DBIx::Class user and developer list
Subject: Re: [Dbix-class] Unknown column in 'group statement'
On Thu, Jul 23, 2009 at 04:19:01PM +0100, Anthony Gladdish wrote:
Hi,
Using:
Perl 5.10.
DBIC 0.08108.
1. My result source tables with relationships are:
Event.pm:
__PACKAGE__-set_primary_key('id');
__PACKAGE__-belongs_to( 'leader' = 'Trainer' ) ;
__PACKAGE__-has_many( 'assistingtrainers' = 'AssistingTrainer', 'event'
);
__PACKAGE__-many_to_many('assistants' = 'assistingtrainers', 'trainers'
);
AssistingTrainer.pm:
__PACKAGE__-set_primary_key('event','trainer');
__PACKAGE__-belongs_to( 'events' = 'Event', 'event' );
__PACKAGE__-belongs_to( 'trainers' = 'Trainer', 'trainer' );
Trainer.pm:
__PACKAGE__-set_primary_key('id');
2. My ResultSet::Event.pm methods:
sub goEvents {
my $self = shift;
my $where = {};
$where-{status} = { '' = 2 };
return $self-search($where);
}
sub events_during_lookback_period {
my $self = shift;
my $default_lookback_period = DateTime::Duration-new( years = 3 );
my $lookback_period = shift || $default_lookback_period;
my $earliest_date = DateTime-now() - $lookback_period;
return $self-goEvents()-search_rs(
{
-and = [
start = { '', DateTime-now() },
start = { '', $earliest_date },
],
}
);
}
sub distinct_assistants {
my $self = shift;
my $assistants = [];
my $rs = $self-search_rs(
undef,
{
columns = [ qw/me.id/ ],
distinct = 1,
prefetch = [ { 'assistingtrainers' = 'trainers' } ],
join = [ { 'assistingtrainers' = 'trainers' } ],
},
);
while ( my $e = $rs-next() ) {
foreach my $at ( $e-assistingtrainers() ) {
push( @$assistants, $at-trainers );
}
}
return $assistants;
}
This is a design lapse - we married distinct with group_by too early
in the code and what you are seeing is the fallout (i.e. distinct
applies to all columns not just the ones you are trying to select).
I will have to discuss this with the rest of the developers before
we solve it, but for the time being simply change
distinct = 1
to
group_by = [ qw/me.id/ ]
The prefetch will keep working as expected.
Cheers
This works, but only if I omit columns = too, i.e.:
{
group_by = [ qw/me.id/ ],
prefetch = [ { 'assistingtrainers' = 'trainers' } ],
join = [ { 'assistingtrainers' = 'trainers' } ],
},
I'm assuming this is ok, although I would have thought columns and
group_by would be needed together (correct me if I'm wrong), and doing this:
{
columns = [ qw/me.id/ ],
group_by = [ qw/me.id/ ],
prefetch = [ { 'assistingtrainers' = 'trainers' } ],
join = [ { 'assistingtrainers' = 'trainers' } ],
},
... produces error:
DBIx::Class::ResultSet::next(): DBI Exception: DBD::mysql::st execute failed:
Unknown column 'start' in 'where clause' [for Statement SELECT me.id,
assistingtrainers.event, assistingtrainers.trainer, trainers.id,
trainers.name, trainers.email, trainers.phone, trainers.initials,
trainers.loginId, trainers.password FROM (SELECT me.id FROM event me WHERE (
( ( start ? AND start ? ) AND status ? ) ) GROUP BY me.id) me LEFT JOIN
trainer_assist assistingtrainers ON assistingtrainers.event = me.id LEFT JOIN
trainer trainers ON trainers.id = assistingtrainers.trainer WHERE ( ( ( start
? AND start ? ) AND status ? ) ) ORDER BY assistingtrainers.event with
ParamValues: 0='2009-07-24T09:46:14', 1='2006-07-24T09:46:14', 2=2,
3='2009-07-24T09:46:14', 4='2006-07-24T09:46:14', 5=2]
This unfortunately is a limitation which can not be worked around easily.
The problem is simple - there is no usable introspection of the WHERE
condition, thus there is no sane way to tell *what* the WHERE limits
on. In your case WHERE is necessary only on the inner query, as it works
on me.* columns only. However since I have no reliable way of determining
this, I err on the safe side, and include the WHERE in the inner and
outer query[1]. The right way to solve this is to bug ash to finish
SQLA2 :) However in the meantime you can trick this with distinct as
such:
{
select = [ { distinct = 'me.id' } ],
as = [qw/id/],
prefetch = [ { 'assistingtrainers' = 'trainers' } ],
join = [ { 'assistingtrainers' = 'trainers' } ],
},
HTH
[1] The reason the double WHERE is
