sql语句的jion 语法

这个sql只是我写的其中一个，随便拿出来的，这个使用的jion 而且对重复的数据去重了。
select a.id,c.name_abbr,a.time,b.name,a.away_id, a.home_id from football_match as a join football_team as b join football_compe
tition as c on a.competition_id = b.competition_id and b.competition_id = c.id where ( a.away_id = 1298 and a.home_id =86) or (a.home_id =1298 and a.away_id = 86 )group by a.id