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.

dbh¶

  my $dbh = $db->dbh;
  $db     = $db->dbh($dbh);

DBD::Pg database handle used for all queries.

  # Use DBI utility methods
  my $quoted = $db->dbh->quote_identifier('foo.bar');

pg¶

  my $pg = $db->pg;
  $db    = $db->pg(Mojo::Pg->new);

Mojo::Pg object this database belongs to.

results_class¶

  my $class = $db->results_class;
  $db       = $db->results_class('MyApp::Results');

Class to be used by "query", defaults to Mojo::Pg::Results. Note that this class needs to have already been loaded before "query" is called.

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.

  # Insert rows in a transaction
  eval {
    my $tx = $db->begin;
    $db->query('insert into frameworks values (?)', 'Catalyst');
    $db->query('insert into frameworks values (?)', 'Mojolicious');
    $tx->commit;
  };
  say $@ if $@;

disconnect¶

  $db->disconnect;

Disconnect "dbh" and prevent it from getting reused.

dollar_only¶

  $db = $db->dollar_only;

Activate "pg_placeholder_dollaronly" for next "query" call and allow "?" to be used as an operator.

  # Check for a key in a JSON document
  $db->dollar_only->query('select * from foo where bar ? $1', 'baz')
    ->expand->hashes->map(sub { $_->{bar}{baz} })->join("\n")->say;

is_listening¶

  my $bool = $db->is_listening;

Check if "dbh" is listening for notifications.

listen¶

  $db = $db->listen('foo');

Subscribe to a channel and receive "notification" events when the Mojo::IOLoop event loop is running.

notify¶

  $db = $db->notify('foo');
  $db = $db->notify(foo => 'bar');

Notify a channel.

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);
  my $results = $db->query('select ?::json as foo', {json => {bar => 'baz'}});

Execute a blocking SQL <http://www.postgresql.org/docs/current/static/sql.html> statement and return a results object based on "results_class" with the query results. The DBD::Pg statement handle will be automatically reused when it is not active anymore, to increase the performance of future queries. You can also append a callback to perform operations non-blocking.

  $db->query('insert into foo values (?, ?, ?)' => @values => sub {
    my ($db, $err, $results) = @_;
    ...
  });
  Mojo::IOLoop->start unless Mojo::IOLoop->is_running;

Hash reference arguments containing a value named "json", will be encoded to JSON text with "to_json" in Mojo::JSON. To accomplish the reverse, you can use the method "expand" in Mojo::Pg::Results, which automatically decodes all fields of the types "json" and "jsonb" with "from_json" in Mojo::JSON to Perl values.

  # "I ♥ Mojolicious!"
  $db->query('select ?::jsonb as foo', {json => {bar => 'I ♥ Mojolicious!'}})
    ->expand->hash->{foo}{bar};

Hash reference arguments containing values named "type" and "value", can be used to bind specific DBD::Pg data types to placeholders.

  # Insert binary data
  use DBD::Pg ':pg_types';
  $db->query('insert into bar values (?)', {type => PG_BYTEA, value => $bytes});

tables¶

  my $tables = $db->tables;

Return table and view names for this database, that are visible to the current user and not internal, as an array reference.

  # Names of all tables
  say for @{$db->tables};

unlisten¶

  $db = $db->unlisten('foo');
  $db = $db->unlisten('*');

Unsubscribe from a channel, "*" can be used to unsubscribe from all channels.