CREATE TABLE PERSON
(P# CHAR(8) NOT NULL UNIQUE,
Pname CHAR(20) NOT NULL,
Page INT,
PRIMARY KEY(P#),CHECK(Page>18))
 
CREATE TABLE ROOM
(R# CHAR(8) NOT NULL UNIQUE,
Rname CHAR(20),
Rarea FLOAT(10),
PRIMARY KEY(R#))

CREATE TABLE PR(
P# CHAR(8) NOT NULL UNIQUE,
R# CHAR(8) NOT NULL UNIQUE,
Date Datetime,

PRIMARY KEY(P#,R#),
FOREIGN KEY(P#) REFERENCES PERSON ON DELETE CASCADE,
FOREIGN KEY(R#) REFERENCES ROOM ON DELETE CASCADE
)