Notes

ADD ATTRIBUTES FROM OLD TABLE TO A NEW ONE :
INSERT INTO STATES
SELECT * FROM STATES_OLD

adding attribute:

ALTER TABLE STATES
ADD AREA NUMBER(7,1)

EX for offices attribute:
CREATE TABLE OFFICES
(state CHAR(2) ,
street_and_number CHAR(30),
zipcode CHAR(8),
phone CHAR(15),
email CHAR(30),
website CHAR(30),
office_number NUMBER(3) PRIMARY KEY,
FOREIGN KEY(state) REFERENCES STATES)

INSERT INTO OFFICES VALUES
('NY','BROOK ST 45','4584','0554869524','[email protected]','www,office1.com','233')

EX for salesman:
CREATE TABLE SALESMAN
(SALESMAN_ID NUMBER(8) PRIMARY KEY,
SURNAME_NAME CHAR(25) NOT NULL,
SECURITY_NUMBER CHAR(11) UNIQUE,
DATE_OF_BIRTH DATE,
ZIP CHAR(30),
SUPERVISOR_ID NUMBER(8),
PHONE_NUMBER CHAR(10),
EMAIL CHAR(30),
OFFICE_NUMBER NUMBER(3),
CITY CHAR(20),
STREET_AND_NUMBER CHAR(20),
STATE CHAR(2),
FOREIGN KEY (OFFICE_NUMBER) REFERENCES OFFICES,
FOREIGN KEY (STATE) REFERENCES STATES )

INSERT INTO SALESMAN VALUES
('001','ASILIOGLU BORA YIGIT','10000000','1995.01.01','2345','10000000','5050651735','[email protected]','233','NEW YORK CITY','WALLACE STREET 55','NY')

CREATE TABLE KNOWS
(SALESMAN_ID NUMBER(8),
LANGUAGE_ID CHAR(3),
LEVEL_OF_LANG CHAR(2) CHECK (LEVEL_OF_LANG in ('A','B','C')),
PRIMARY KEY(SALESMAN_ID,LANGUAGE_ID),
FOREIGN KEY (SALESMAN_ID) REFERENCES SALESMAN,
FOREIGN KEY(LANGUAGE_ID) REFERENCES LANGUAGES)