Database Integration¶

DBI¶

Amon2 provides Amon2::DBI with splitted package Amon2-DBI.

Amon2::DBI provides the following features on DBI:

Better error message

RAII style transaction management(DBIx::TransactionManager)

SQL construction helper(with SQL::Interp)

You can install it by following this one liner:

% curl -L http://cpanmin.us | perl - Amon2::DBI

And it contains Amon2::Plugin::DBI. You can use the plugin as:

package MyApp;
__PACKAGE__->load_plugin(qw/DBI/);

Then you can access the instance of DBI, you can call $c->dbh.

Transaction management¶

You can use it as follows:

my $dbh = Amon2::DBI->connect(...);
my $txn = $dbh->txn_scope();
...
$txn->commit();

You can handle nested transactions.

For more details please access DBIx::TransactionManager.

SQL helper¶

For your convenience, Amon2::DBI provides the following helper methods.

$dbh->do_i(@args)¶

This method constructs SQL using SQL::Interp::sql_interp and executes it.

$dbh->insert($table, %row);¶

This is equivalent to:

$dbh->do_i(qq{INSERT INTO $table }, \%row);

Teng¶

Amon2 does not support any specific O/R Mapper by default. But you can integrate any O/R mapper very easily!

This article provides tutorial for using Teng with Amon2.

And write a constructor for context object:

package MyApp;
use parent qw/Amon2/;
use Teng::Schema::Loader;
use Teng;

sub db {
    my $self = shift;
    if ( !defined $self->{db} ) {
        my $conf = $self->config->{'DB'}
          or die "missing configuration for 'DB'";
        my $dbh = DBI->connect($conf);
        my $schema = Teng::Schema::Loader->load(
            namespace => 'MyApp::DB',
            dbh       => $dbh,
        );
        $self->{db} = Teng->new(
            dbh    => $dbh,
            schema => $schema,
        );
    }
    return $self->{db};
}

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