외래키

[Oracle] CONSTRAINT(제약조건)_FOREIGN KEY(외래키)

회원등급에 대한 데이터를 따로 보관하는 테이블 CREATE TABLE MEM_GRADE( GRADE_CODE NUMBER PRIMARY KEY, GRADE_NAME VARCHAR2(30) NOT NULL ); INSERT INTO MEM_GRADE VALUES(10, '일반회원'); INSERT INTO MEM_GRADE VALUES(20, '우수회원'); INSERT INTO MEM_GRADE VALUES(30, '특별회원'); CREATE TABLE MEM( MEM_NO NUMBER PRIMARY KEY, MEM_ID VARCHAR2(20) NOT NULL UNIQUE, MEM_PWD VARCHAR2(20) NOT NULL, MEM_NAME VARCHAR2(20) NOT NULL, GENDER CHA..