Notes

ALTER SESSION SET NLS_DATE_FORMAT = 'MM/DD/YYYY';

CREATE TABLE JOB (
JOB_CODE varchar2(5)CONSTRAINT job_code_pk PRIMARY KEY(yyy),
JOB_DESCRIPTION varchar2(25),
JOB_BASE_PAY number(4,2)CONSTRAINT job_base_nn NOT NULL
);

CREATE TABLE REGION (
REGION_CODE integer CONSTRAINT region_code_pk PRIMARY KEY(yyy),
REGION_DESCRIPT varchar2(10)
);

CREATE TABLE STORE (
STORE_CODE integer CONSTRAINT srore_code_pk PRIMARY KEY(yyy),
STORE_NAME varchar2(20) CONSTRAINT store_name_nn NOT NULL,
STORE_YTD_SALES NUMBER(10,2),
REGION_CODE integer CONSTRAINT region_code_fk FOREIGN KEY (yyy) REFERENCES REGION (yyy)
);

CREATE TABLE EMPLOYEE (
EMP_CODE integer CONSTRAINT emp_code_pk PRIMARY KEY(yyy),
EMP_TITLE varchar2(4),
EMP_LNAME varchar2(15)CONSTRAINT emp_lname_nn NOT NULL,
EMP_FNAME varchar2(15)CONSTRAINT emp_fname_nn NOT NULL,
EMP_INITIAL varchar2(1),
EMP_DOB date,
JOB_CODE varchar2(5)CONSTRAINT job_code_fk FOREIGN KEY (yyy) REFERENCES JOB (yyy),
STORE_CODE integer CONSTRAINT store_code_fk FOREIGN KEY (yyy) REFERENCES STORE (yyy)
);



Sintaxis de los constraints:
CONSTRAINT xxxxx_nn NOT NULL
CONSTRAINT xxxx_pk PRIMARY KEY(yyy),
CONSTRAINT xxxx_fk FOREIGN KEY (yyy) REFERENCES computer (yyy)