Code Igniter Session Table creation.

CI Session Table Creation

CREATE TABLE IF NOT EXISTS  `ci_sessions` (
  session_id varchar(40) DEFAULT '0' NOT NULL,
	ip_address varchar(45) DEFAULT '0' NOT NULL,
	user_agent varchar(120) NOT NULL,
	last_activity int(10) unsigned DEFAULT 0 NOT NULL,
	user_data text NOT NULL,
	PRIMARY KEY (session_id),
	KEY `last_activity_idx` (`last_activity`)
);