Matching fighters from a single table - mysql

Question

I have a table with fighter records and I need to match them accordingly by level, weight, sex and type of fight sport. This is the structure of the table
CREATE TABLE `tfc_sparring_requests_athletes` (
`id` bigint(20) NOT NULL AUTO_INCREMENT,
`fullname` varchar(300) DEFAULT NULL,
`birthdate` date DEFAULT NULL,
`weight` float DEFAULT NULL,
`fightsport` int(11) DEFAULT NULL,
`sex` int(11) DEFAULT NULL,
`level` int(11) DEFAULT NULL,
`teamid` int(11) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=31 DEFAULT CHARSET=utf8
I tried to make a query like this in order to match the fighters
select a.fullname,b.fullname,a.weight
from tfc_sparring_requests_athletes a ,
tfc_sparring_requests_athletes b
where a.weight = b.weight
and a.fightsport = b.fightsport
and a.level =b.level
and a.sex = b.sex
and a.fullname != b.fullname
and the result is
fighter23 fighter1 78
fighter6 fighter5 70
fighter5 fighter6 70
fighter1 fighter23 78
fighter26 fighter25 57
fighter25 fighter26 57
fighter28 fighter27 80
fighter27 fighter28 80
As you can see fighter 1 is matched with fighter 23 in row 1 but in row 4 fighters appear again. Also other fighters repeat their match as well like fighter 5 and 6 in row 2 and 3. How can I avoid this repetition so I can show the matches uniquely?

Answer 1

Anyway I found the solution based on this question How to select distinct pairs in MySQL join (same table) with transitivity?
select MIN(a.id),b.id,a.fullname name1,b.fullname name2,a.weight
from tfc_sparring_requests_athletes a ,tfc_sparring_requests_athletes b
where a.weight = b.weight
and a.fightsport = b.fightsport
and a.level =b.level
and a.sex = b.sex
and a.fullname != b.fullname
AND b.id > a.id
GROUP BY b.id;