재밌네요.. 숙제인가요? 

테이블은 ddl문으로 짜서 드려야되나요? 아니면 erd 로?

http://gurubee.net/oracle/sql

CREATE TABLE department
( dept_code  CHAR(2)      NOT NULL
, dept_name  VARCHAR2(30)
, CONSTRAINT pk_department PRIMARY KEY (dept_code)
)
;

CREATE TABLE profesor
( prof_code  CHAR(2)      NOT NULL
, prof_name  VARCHAR2(10)
, CONSTRAINT pk_profesor PRIMARY KEY (prof_code)
)
;

CREATE TABLE student
( s_number  NUMBER(7)    NOT NULL
, s_name    VARCHAR2(10) NOT NULL
, dept_code CHAR(2)
, grade     NUMBER(1)
, address   VARCHAR2(50)
, email     VARCHAR2(20)
, phone     VARCHAR2(13)
, birth     CHAR(8)      DEFAULT TO_CHAR(sysdate, 'yyyymmdd')
, prof_code CHAR(2)
, CONSTRAINT pk_student PRIMARY KEY (s_number)
, CONSTRAINT uk_student_email UNIQUE (email)
, CONSTRAINT ck_student_grade CHECK (grade IN (1, 2, 3))
, CONSTRAINT fk_student_dept_code FOREIGN KEY (dept_code) REFERENCES department(dept_code) ON DELETE CASCADE
, CONSTRAINT fk_student_prof_code FOREIGN KEY (prof_code) REFERENCES   profesor(prof_code) ON DELETE CASCADE
)
;