SQL Training #22 - 25 SQL JOIN 관련해서 정보
SQL Training #22 - 25 SQL JOIN 관련해서본문
Department에 대한 테이블 작성을 합니다.
create table simpledb.department
(
department_number int primary key,
department_name varchar(50),
location varchar(50)
);
insert into simpledb.department (department_number, department_name, location) values (10, 'ACCOUNTING', 'NEW YORK');
insert into simpledb.department (department_number, department_name, location) values (20, 'RESEARCH', 'DALLAS');
insert into simpledb.department (department_number, department_name, location) values (30, 'SALES', 'CHICAGO');
insert into simpledb.department (department_number, department_name, location) values (40, 'OPERATIONS', 'BOSTO');
SQL Inner Join
select * from simpledb.department;
select *
from simpledb.employee
inner join simpledb.department
on employee.department_number = department.department_number;
select department.department_name, employee.*
from simpledb.employee
inner join simpledb.department
on employee.department_number = department.department_number;
select d.department_name, e.*
from simpledb.employee as e
inner join simpledb.department as d
on e.department_number = d.department_number;
select d.department_name, e.*
from simpledb.employee as e
inner join simpledb.department as d
on e.department_number = d.department_number
where d.department_name='Sales';
https://www.youtube.com/watch?v=yMOmuFiw__Y&list=PLD20298E653A970F8&index=22
SQL Outer Join
join만 쓰면 inner join과 같네요.
select * from simpledb.customer
join simpledb.employee
on customer.saleman_employee_number=employee.employee_number;
select * from simpledb.customer
left outer join simpledb.employee
on customer.saleman_employee_number=employee.employee_number;
https://www.youtube.com/watch?v=ge9aXvDhjnw&list=PLD20298E653A970F8&index=23
SQL Right Outer Join
select * from simpledb.employee
inner join simpledb.customer
on employee.employee_number=customer.saleman_employee_number;
select * from simpledb.employee
right outer join simpledb.customer
on employee.employee_number=customer.saleman_employee_number;
select * from simpledb.customer
left outer join simpledb.employee
on customer.saleman_employee_number=employee.employee_number;
https://www.youtube.com/watch?v=DiKNwdnX9Io&list=PLD20298E653A970F8&index=24
SQL Left Outer Join
select * from simpledb.customer
inner join simpledb.employee
on customer.saleman_employee_number=employee.employee_number;
select * from simpledb.customer
left outer join simpledb.employee
on customer.saleman_employee_number=employee.employee_number;
https://www.youtube.com/watch?v=BuVd9_UQyrQ&list=PLD20298E653A970F8&index=25
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