[MySQL] INNER JOIN / LEFT JOIN / RIGHT JOIN (초간단 예제)

 

create database join_test;

 

create table person(  id int, name varchar(30)  );

create table order_(  order_id int, person_id int  );

 

insert into person values (1, "a");

insert into person values (2, "b");

insert into person values (3, "c");

 

insert into order_ values (1, 3);

insert into order_ values (2, 6);

insert into order_ values (3, 9);

 

위의 쿼리를 통해서 테이블 두개를 만들었다.

order는 예약어인지 테이블 생성이 안돼서 언더바를 붙였다.

 

 

1. INNER JOIN

select p.id, p.name, o.order_id from person as p join order_ as o on p.id = o.person_id;

2. LEFT JOIN

select p.id, p.name, o.order_id from person as p left join order_ as o on p.id = o.person_id;

 

 

3. RIGHT JOIN

select p.id, p.name, o.order_id from person as p right join order_ as o on p.id = o.person_id;

 

 

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