CREATE TABLE Customer(
	customerID NUMBER,
	firstName VARCHAR2(15),
	lastName VARCHAR2(15),
	address VARCHAR2(30),
	phone NUMBER(10),
	CONSTRAINT Customer_pk PRIMARY KEY(customerID),
	CONSTRAINT Customer_U1 UNIQUE(firstName, lastName, phone),
	CONSTRAINT Customer_phoneNumber_Val CHECK (phone IS NOT NULL)
);
CREATE SEQUENCE customerID_seq;

CREATE TABLE Company(
	companyName VARCHAR2(15),
	stockSymbol CHAR(4),
	website VARCHAR2(40),
	CONSTRAINT Company_pk PRIMARY KEY(companyName),
	CONSTRAINT Company_stockSymbol_U UNIQUE(stockSymbol)
);

CREATE TABLE Cruise(
	cruiseID NUMBER,
	cruiseName VARCHAR2(25),
	departurePort VARCHAR2(20),
	days NUMBER(2),
	companyName VARCHAR2(15),
	shipName VARCHAR2(30),
	price NUMBER(7, 2),
	CONSTRAINT Cruise_pk PRIMARY KEY(cruiseID),
	CONSTRAINT Cruise_companyName_fk FOREIGN KEY (companyName) REFERENCES Company(companyName)
);
CREATE SEQUENCE cruiseID_seq;

CREATE TABLE TravelAgent(
	travelAgentID NUMBER,
	firstName VARCHAR2(15),
	lastName VARCHAR2(20),
	title VARCHAR2(15),
	salary NUMBER(7, 2),
	CONSTRAINT TravelAgent_pk PRIMARY KEY(travelAgentID)
);
CREATE SEQUENCE travelAgentID_seq;

CREATE TABLE Reservation(
	reservationID NUMBER,
	customerID NUMBER,
	cruiseID NUMBER,
	travelAgentID NUMBER,
	travelDate DATE,
	CONSTRAINT Reservation_pk PRIMARY KEY(reservationID),
	CONSTRAINT Reservation_customerID_fk FOREIGN KEY (customerID) REFERENCES Customer(customerID),
	CONSTRAINT Reservation_cruiseID_fk FOREIGN KEY (cruiseID) REFERENCES Cruise(cruiseID),
	CONSTRAINT Reservation_travelAgentID_fk FOREIGN KEY (travelAgentID) REFERENCES TravelAgent(travelAgentID)
);
CREATE SEQUENCE reservationID_seq;