mysql custom global defined variable

In my database design, I tend to store some variable that is meant to be acting as a ROLE or TYPE as SMALLINT. For example : CREATE TABLE house ( id int(11) NOT NULL AUTO_INCREMENT, type smallint(11) NOT NULL, ) And in php, I do define('HOUSE_SMALL_TYPE', '0'); define('HOUSE_MEDIUM_TYPE', '1'); So in php, in SELECT queries I do : $this->db->query("SELECT * FROM house WHERE type=?;", HOUSE_SMALL_TYPE); My questions are : 1. In the php part, is there is a better way to do this ? 2. In the mysql itself, does mysql also has global define functionality (like the define in php) ? I also want to do kind of SELECT * FROM house WHERE type = HOUSE_SMALL_TYPE in mysql query.