[오라클/SQL] 컬럼에 외래키 제약 추가하기 ( ALTER TABLE )

SQL FOREIGN KEY Constraint on ALTER TABLE

- 외래키 추가하기

MySQL / SQL Server / Oracle / MS Access:

ALTER TABLE Orders
ADD FOREIGN KEY (P_Id)
REFERENCES Persons(P_Id)

- 외래키 이름 지정해주기

MySQL / SQL Server / Oracle / MS Access:

ALTER TABLE Orders
ADD CONSTRAINT fk_PerOrders
FOREIGN KEY (P_Id)
REFERENCES Persons(P_Id)

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To DROP a FOREIGN KEY Constraint

- 외래키 삭제하기 

MySQL:

ALTER TABLE Orders
DROP FOREIGN KEY fk_PerOrders

SQL Server / Oracle / MS Access:

ALTER TABLE Orders
DROP CONSTRAINT fk_PerOrders