Mysql - Three table query
===

I have three tables which are used to store some user data

sub_domains (experience sub domains go here. exp_id matches id in exp and domain_id matches id in misc. So the user_id and exp_id can be duplicate if a user has more than one sub domain)

    +-----------+---------+------+-----+---------+----------------+
    | Field     | Type    | Null | Key | Default | Extra          |
    +-----------+---------+------+-----+---------+----------------+
    | id        | int(11) | NO   | PRI | NULL    | auto_increment |
    | user_id   | int(50) | YES  |     | NULL    |                |
    | domain_id | int(10) | NO   |     | NULL    |                |
    | exp_id    | int(50) | YES  |     | NULL    |                |
    +-----------+---------+------+-----+---------+----------------+

misc

    +----------+--------------+------+-----+---------+----------------+
    | Field    | Type         | Null | Key | Default | Extra          |
    +----------+--------------+------+-----+---------+----------------+
    | id       | int(11)      | NO   | PRI | NULL    | auto_increment |
    | name     | varchar(100) | YES  |     | NULL    |                |
    | category | varchar(255) | YES  |     | NULL    |                |
    +----------+--------------+------+-----+---------+----------------+

exp

    +------------+--------------+------+-----+---------+----------------+
    | Field      | Type         | Null | Key | Default | Extra          |
    +------------+--------------+------+-----+---------+----------------+
    | id         | int(11)      | NO   | PRI | NULL    | auto_increment |
    | user_id    | int(11)      | YES  |     | NULL    |                |
    | job_type   | varchar(60)  | YES  |     | NULL    |                |
    | experience | varchar(500) | YES  |     | NULL    |                |
    | exp_title  | varchar(255) | YES  |     | NULL    |                |
    | domain     | varchar(125) | YES  |     | NULL    |                |
    | start      | varchar(20)  | YES  |     | NULL    |                |
    | end        | varchar(20)  | YES  |     | NULL    |                |
    +------------+--------------+------+-----+---------+----------------+

This is the query I have atm that grabs data from exp:

    $query_str = "SELECT a.id, a.user_id, a.job_type, a.experience, a.exp_title, a.domain,     a.start, a.end, b.name
    FROM exp a
    JOIN misc b ON a.domain=b.id
    WHERE a.user_id = ?";

I am already getting the domain name from misc but I also want to get the name of each sub domain from misc also but I don t know how to change the query. 