Legacy_Upgrades::upgrade_to_1_0_4()

	protected function upgrade_to_1_0_4() {
		global $wpdb;

		$containers = $this->get_full_table_name( 'containers' );
		$elements = $this->get_full_table_name( 'elements' );
		$charset_collate = $wpdb->get_charset_collate();

		$sql = "CREATE TABLE $containers (
			id int(11) NOT NULL AUTO_INCREMENT,
			form_id int(11) NOT NULL,
			label text NOT NULL,
			sort int(11) NOT NULL,
			UNIQUE KEY id (id)
			) ENGINE = INNODB " . $charset_collate . ";";

		dbDelta( $sql );

		$wpdb->query( "ALTER TABLE $elements ADD container_id INT(11) NOT NULL AFTER form_id" );
	}