# NAME Plack::Middleware::Debug::DBIC::QueryLog - Log DBIC Queries ## SYNOPSIS Adds a debug panel and querylog object for logging [DBIx::Class](http://search.cpan.org/perldoc?DBIx::Class) queries. Has support for [Catalyst](http://search.cpan.org/perldoc?Catalyst) via a [Catalyst::TraitFor::Model::DBIC::Schema::QueryLog](http://search.cpan.org/perldoc?Catalyst::TraitFor::Model::DBIC::Schema::QueryLog) compatible trait, [Catalyst::TraitFor::Model::DBIC::Schema::QueryLog::AdoptPlack](http://search.cpan.org/perldoc?Catalyst::TraitFor::Model::DBIC::Schema::QueryLog::AdoptPlack). use Plack::Builder; my $app = ...; ## Build your Plack App builder { enable 'Debug::DBIC::QueryLog', querylog_args => {passthrough => 1}; $app; }; And in you [Catalyst](http://search.cpan.org/perldoc?Catalyst) application, if you are also using [Catalyst::TraitFor::Model::DBIC::Schema::QueryLog::AdoptPlack](http://search.cpan.org/perldoc?Catalyst::TraitFor::Model::DBIC::Schema::QueryLog::AdoptPlack) package MyApp::Web::Model::Schema; use parent 'Catalyst::Model::DBIC::Schema'; __PACKAGE__->config({ schema_class => 'MyApp::Schema', traits => ['QueryLog::AdoptPlack'], ## .. rest of configuration }); 1; # DESCRIPTION [DBIx::Class::QueryLog](http://search.cpan.org/perldoc?DBIx::Class::QueryLog) is a tool in the [DBIx::Class](http://search.cpan.org/perldoc?DBIx::Class) software ecosystem which benchmarks queries. It lets you log the SQL that [DBIx::Class](http://search.cpan.org/perldoc?DBIx::Class) is generating, along with bind variables and timestamps. You can then pass the querylog object to an analyzer (such as [DBIx::Class::QueryLog::Analyzer](http://search.cpan.org/perldoc?DBIx::Class::QueryLog::Analyzer)) to generate sorted statistics for all the queries between certain log points. Query logging in [Catalyst](http://search.cpan.org/perldoc?Catalyst) is supported for [DBIx::Class](http://search.cpan.org/perldoc?DBIx::Class) via a trait for [Catalyst::Model::DBIC::Schema](http://search.cpan.org/perldoc?Catalyst::Model::DBIC::Schema) called [Catalyst::TraitFor::Model::DBIC::Schema::QueryLog](http://search.cpan.org/perldoc?Catalyst::TraitFor::Model::DBIC::Schema::QueryLog). This trait will log all the SQL used by [DBIx::Class](http://search.cpan.org/perldoc?DBIx::Class) for a given request cycle. This is very useful since it can help you identify troublesome or bottlenecking queries. However, [Catalyst::TraitFor::Model::DBIC::Schema::QueryLog](http://search.cpan.org/perldoc?Catalyst::TraitFor::Model::DBIC::Schema::QueryLog) does not provide out of the box outputting of your analyzed query logs. Usually you need to add a bit of templating work to the bottom of your webpage footer, or dump the output to the logs. We'd like to provide a lower ceremony experience. Additionally, it would be nice if we could provide this functionality for all [Plack](http://search.cpan.org/perldoc?Plack) based applications, not just [Catalyst](http://search.cpan.org/perldoc?Catalyst). Ideally we'd play nice with [Plack::Middleware::Debug](http://search.cpan.org/perldoc?Plack::Middleware::Debug) so that the table of our querylog would appear as a neat Plack based Debug panel. This bit of middleware provides that function. Basically we create a new instance of [DBIx::Class::QueryLog](http://search.cpan.org/perldoc?DBIx::Class::QueryLog) and place it into `$env->{'plack.middleware.debug.dbic.querylog'}` so that it is accessible by all applications running inside of [Plack](http://search.cpan.org/perldoc?Plack). You need to 'tell' your application's instance of [DBIx::Class](http://search.cpan.org/perldoc?DBIx::Class) to use this `$env` key and make sure you set [DBIx::Class](http://search.cpan.org/perldoc?DBIx::Class)'s debug object correctly: my $querylog = $ctx->engine->env->{'plack.middleware.debug.dbic.querylog'}; $schema->storage->debugobj($querylog); $schema->storage->debug(1); That way when you view the debug panel, we have SQL to review. If you are using [Catalyst](http://search.cpan.org/perldoc?Catalyst) and a modern [Catalyst::Model::DBIC::Schema](http://search.cpan.org/perldoc?Catalyst::Model::DBIC::Schema) you can use the trait [Catalyst::TraitFor::Model::DBIC::Schema::QueryLog::AdoptPlack](http://search.cpan.org/perldoc?Catalyst::TraitFor::Model::DBIC::Schema::QueryLog::AdoptPlack), which is compatible with [Catalyst::TraitFor::Model::DBIC::Schema::QueryLog](http://search.cpan.org/perldoc?Catalyst::TraitFor::Model::DBIC::Schema::QueryLog). See the L example for more details. # OPTIONS This debug panel defines the following options. ## querylog Takes a [DBIx::Class::QueryLog](http://search.cpan.org/perldoc?DBIx::Class::QueryLog) object, which is used as the querylog for the application. If you don't provide this, we will build one automatically, using L if provided. Generally you will use this only if you are instantiating a querylog object outside your [Plack](http://search.cpan.org/perldoc?Plack) based application, such as in an IOC container like [Bread::Board](http://search.cpan.org/perldoc?Bread::Board). ## querylog_args Takes a HashRef which is passed to [DBIx::Class::QueryLog](http://search.cpan.org/perldoc?DBIx::Class::QueryLog) at construction. # SEE ALSO [Plack::Middleware::Debug](http://search.cpan.org/perldoc?Plack::Middleware::Debug), [Catalyst::TraitFor::Model::DBIC::Schema::QueryLog](http://search.cpan.org/perldoc?Catalyst::TraitFor::Model::DBIC::Schema::QueryLog), [Catalyst::Model::DBIC::Schema](http://search.cpan.org/perldoc?Catalyst::Model::DBIC::Schema), [Catalyst::TraitFor::Model::DBIC::Schema::QueryLog::AdoptPlack](http://search.cpan.org/perldoc?Catalyst::TraitFor::Model::DBIC::Schema::QueryLog::AdoptPlack) # AUTHOR John Napiorkowski, `` # COPYRIGHT & LICENSE This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.