CREATE TABLE Exam ( moduleNo CHAR(8) NOT NULL, date DATE NOT NULL, PRIMARY KEY ( moduleNo ) ); CREATE TABLE Question ( questionNumber INT NOT NULL, moduleNo CHAR(8) REFERENCES Exam ( moduleNo) , text VARCHAR(20) NOT NULL, PRIMARY KEY ( moduleNo, questionNumber ) ); CREATE TABLE Answer ( option CHAR(1) NOT NULL, questionNumber INT REFERENCES Question ( questionNumber) , moduleNo CHAR(8) REFERENCES Exam ( moduleNo) , correct VARCHAR(20) NOT NULL, text VARCHAR(20) NOT NULL, PRIMARY KEY ( moduleNo, questionNumber, option ) );