SELECT ufirstname,class_time_r.tid 
FROM users 
LEFT JOIN class_user_r ON users.uid=class_user_r.uid
LEFT JOIN class_time_r ON class_user_r.cid=class_time_r.cid 
WHERE ufirstname='Connie' ORDER BY tid DESC;

+------------+------+
| ufirstname | tid  |
+------------+------+
| Connie     |   20 | 
| Connie     |   19 | 
| Connie     |   18 | 
| Connie     |   17 | 
+------------+------+