[JPA] JPQL - join 예시

[기본 join 문]

 

1. inner join (inner 생략 가능)

SELECT m FROM Member as m inner join m.team t
	where t.name = :teamName";
    
query 문 
-> select m.* from member m join team t on m.team_id = t.id

 

2. outer join (left/right)

SELECT m FROM Member as m left join m.team t;

query문
-> select m.*, t.* from member m left join team t on m.team_id = t.id

 

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[조인 대상 필터링]  + on

SELECT m FROM Member as m inner join m.team t on t.name='A'

query문 
-> select m.* from member m join team t on m.team_id = t.id and t.name='A'

 

[연관관계 없는 엔티티 외부 조인]

SELECT m FROM Member as m inner join m.team t on m.username = t.name";

query문 
-> select m.* from member m join team t on m.usernmae = t.name;