Table creation for scheduling.

create-table.php

private function do_table() {
		global $wpdb;

		$charset_collate = $wpdb->get_charset_collate();

		$sql = "CREATE TABLE $this->table_name (
		  id mediumint(9) NOT NULL AUTO_INCREMENT,
		  created datetime DEFAULT '0000-00-00 00:00:00' NOT NULL,
		  modified datetime DEFAULT '0000-00-00 00:00:00' NOT NULL,
		  interval TEXT NOT NULL,
		  object_type TEXT NOT NULL,
		  PRIMARY KEY  (id)
		) $charset_collate;";

		require_once( ABSPATH . 'wp-admin/includes/upgrade.php' );
		dbDelta( $sql );
}