Help with MySQL join 3 Tables - mysql

Question

I am working on a registration system that uses the following tables:
Person (name etc.), Course (course date), Registration (association table pid, cid)
Person
+-------+---------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+---------+------+-----+---------+-------+
| id | int(11) | NO | PRI | NULL | |
| name | text | YES | | NULL | |
+-------+---------+------+-----+---------+-------+
Example Data:
select * from person;
+-----+--------+
| id | name |
+-----+--------+
| 101 | Graham |
| 102 | Lisa |
| 103 | John |
+-----+--------+
Course
+-------+---------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+---------+------+-----+---------+-------+
| id | int(11) | NO | PRI | NULL | |
| name | text | YES | | NULL | |
| date | date | YES | | NULL | |
+-------+---------+------+-----+---------+-------+
select * from course;
+----+---------+------------+
| id | name | date |
+----+---------+------------+
| 1 | Hip Hop | 2011-06-08 |
| 2 | Dancing | 2006-06-23 |
| 3 | Running | 2007-07-08 |
+----+---------+------------+
Registration
+-------+---------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+---------+------+-----+---------+-------+
| id | int(11) | NO | PRI | NULL | |
| pid | int(11) | YES | | NULL | |
| cid | int(11) | YES | | NULL | |
+-------+---------+------+-----+---------+-------+
select * from registration;
+----+------+------+
| id | pid | cid |
+----+------+------+
| 1 | 101 | 1 |
| 2 | 101 | 2 |
| 3 | 103 | 2 |
+----+------+------+
I would like to find person(s) that have no registration records within the past two years. I am attempting to join the tables based on date calculation but it does not seem to work this way. Is this possible with mysql or is my approach of trying this with one query wrong?
query I have come up with:
select * from
(person left join registration on person.id = registration.pid)
left join course on course.id = registration.cid
AND DATE_FORMAT(`course`.`date`, "%m.%Y") > DATE_FORMAT( DATE_SUB(NOW(), INTERVAL 2 YEAR),"%m.%Y")
WHERE
registration.id IS NULL;
+-----+------+------+------+------+------+------+------+
| id | name | id | pid | cid | id | name | date |
+-----+------+------+------+------+------+------+------+
| 102 | Lisa | NULL | NULL | NULL | NULL | NULL | NULL |
+-----+------+------+------+------+------+------+------+
It should list person 102 and 103 since both registrations are older than 2 years and no other records of newer course dates can be found...

Answer 1

Give this a shot, using a NOT EXISTS clause:
select p.* from person p
where not exists (select 1 from person px
join registration rx on px.id = rx.pid
join course cx on rx.cid = cx.id
where px.id = p.id
and cx.date > DATE_SUB(NOW(), INTERVAL 2 YEAR))