NAME
Mojo::Pg::Database - Database
SYNOPSIS
use Mojo::Pg::Database;
my $db = Mojo::Pg::Database->new(pg => $pg, dbh => $dbh);
$db->query('select * from foo')->hashes
->map(sub { $_->{bar} })->join("\n")->say;DESCRIPTION
Mojo::Pg::Database is a container for DBD::Pg database handles used by Mojo::Pg.
EVENTS
Mojo::Pg::Database inherits all events from Mojo::EventEmitter and can emit the following new ones.
close
$db->on(close => sub {
my $db = shift;
...
});Emitted when the database connection gets closed while waiting for notifications.
notification
$db->on(notification => sub {
my ($db, $name, $pid, $payload) = @_;
...
});Emitted when a notification has been received.
ATTRIBUTES
Mojo::Pg::Database implements the following attributes.
dbh
my $dbh = $db->dbh;
$db = $db->dbh(DBI->new);DBD::Pg database handle used for all queries.
pg
my $pg = $db->pg;
$db = $db->pg(Mojo::Pg->new);Mojo::Pg object this database belongs to.
max_statements
my $max = $db->max_statements;
$db = $db->max_statements(5);Maximum number of statement handles to cache for future queries, defaults to 10.
METHODS
Mojo::Pg::Database inherits all methods from Mojo::EventEmitter and implements the following new ones.
backlog
my $num = $db->backlog;Number of waiting non-blocking queries.
begin
my $tx = $db->begin;Begin transaction and return Mojo::Pg::Transaction object, which will automatically roll back the transaction unless "commit" in Mojo::Pg::Transaction has been called before it is destroyed.
my $tx = $db->begin;
$db->query('insert into names values (?)', 'Baerbel');
$db->query('insert into names values (?)', 'Wolfgang');
$tx->commit;disconnect
$db->disconnect;Disconnect "dbh" and prevent it from getting cached again.
do
$db = $db->do('create table foo (bar text)');Execute a statement and discard its result.
is_listening
my $bool = $db->is_listening;Check if "dbh" is listening for notifications.
listen
$db = $db->listen('foo');Start listening for notifications when the Mojo::IOLoop event loop is running.
notify
$db = $db->notify('foo');
$db = $db->notify('foo', 'bar');Send notification with optional payload.
pid
my $pid = $db->pid;Return the process id of the backend server process.
ping
my $bool = $db->ping;Check database connection.
query
my $results = $db->query('select * from foo');
my $results = $db->query('insert into foo values (?, ?, ?)', @values);Execute a blocking statement and return a Mojo::Pg::Results object with the results. The DBD::Pg statement handle will be automatically cached again when that object is destroyed, so future queries can reuse it to increase performance. You can also append a callback to perform operation non-blocking.
$db->query('insert into foo values (?, ?, ?)' => @values => sub {
my ($db, $err, $results) = @_;
...
});
Mojo::IOLoop->start unless Mojo::IOLoop->is_running;unlisten
$db = $db->unlisten('foo');
$db = $db->unlisten('*');Stop listening for notifications.