DB를 구축하거나 구정할 목적으로 사용하는 언어
: CREATE, ALTER, DROP
(ALTER) TABEL 학생 (ADD) VARCHAR(20);
CREATE INDEX 'name_idx' ON student(name);
CREATE INDEX '직원_NAME' ON 직원(이름);
CREATE UNIQUE INDEX 'Stud_idx' ON student(ssn asc);
CREATE TABLE patient(id VARCHAR(5) PRIMARY KEY, name VARCHAR(10), sex VARCHAR(1), phone VARCHAR(20),
CONSTRAINT sex_ck CHECK (sex='f' or sex='m'),
CONSTRAINT id_fk FOREIGN KEY(id) REFERENCES doctor(doc_id));
CREATE TABLE INSTRUCTOR(NAME VARCHAR(15) NOT NULL PRIMARY KEY,
DEPT VARCHAR(15), FOREIGN KEY(DEPT) REFERENCES DEPARTMENT(DEPT)
ON DELETE SET NULL ON UPDATE CASCADE;
ALTER TABLE PATIENT ADD JOB VARCHAR(20);
CREATE VIEW CC(CCID, CCNAME, INSTNAME)
AS SELECT COURSE.ID, COURSE.NAME, INSTRUCTOR.NAME
FROM COURSE, INSTRUCTOR
WHERE COURSE.INSTRUCTOR = INSTRUCTOR.ID;
CREATE DOMIAN 직위 VARCHAR(10)
DEFAULT '사원'
CONSTRAINT VALID-직위 CHECK
(VALUE IN('사원', '과장', '부장', '이사', '사장'));