test_database/online_exams/simple_schema.sql

CREATE TABLE Students (
Student_ID INTEGER NOT NULL,
First_Name VARCHAR(255),
Middle_Name VARCHAR(255),
Last_Name VARCHAR(255),
Gender_MFU CHAR(1),
Student_Address VARCHAR(255),
Email_Adress VARCHAR(255),
Cell_Mobile_Phone VARCHAR(255),
Home_Phone VARCHAR(255),
PRIMARY KEY (Student_ID)
);
CREATE TABLE Questions (
Question_ID INTEGER NOT NULL,
Type_of_Question_Code VARCHAR(15) NOT NULL,
Question_Text VARCHAR(255),
PRIMARY KEY (Question_ID)
);
CREATE TABLE Exams (
Exam_ID INTEGER NOT NULL,
Subject_Code CHAR(15) NOT NULL,
Exam_Date DATETIME,
Exam_Name VARCHAR(255),
PRIMARY KEY (Exam_ID)
);
CREATE TABLE Questions_in_Exams (
Exam_ID INTEGER NOT NULL,
Question_ID INTEGER NOT NULL,
PRIMARY KEY (Exam_ID, Question_ID),
FOREIGN KEY (Question_ID) REFERENCES Questions (Question_ID),
FOREIGN KEY (Exam_ID) REFERENCES Exams (Exam_ID)
);
CREATE TABLE Valid_Answers (
Valid_Answer_ID INTEGER NOT NULL,
Question_ID INTEGER NOT NULL,
Valid_Answer_Text VARCHAR(255),
PRIMARY KEY (Valid_Answer_ID),
FOREIGN KEY (Question_ID) REFERENCES Questions (Question_ID)
);
CREATE TABLE Student_Answers (
Student_Answer_ID INTEGER NOT NULL,
Exam_ID INTEGER NOT NULL,
Question_ID INTEGER NOT NULL,
Student_ID INTEGER NOT NULL,
Date_of_Answer DATETIME,
Comments VARCHAR(255),
Satisfactory_YN VARCHAR(1),
Student_Answer_Text VARCHAR(255),
PRIMARY KEY (Student_Answer_ID),
FOREIGN KEY (Student_ID) REFERENCES Students (Student_ID),
FOREIGN KEY (Exam_ID, Question_ID) REFERENCES Questions_in_Exams (Exam_ID,Question_ID)
);
CREATE TABLE Student_Assessments (
Student_Answer_ID VARCHAR(100) NOT NULL,
Valid_Answer_ID INTEGER NOT NULL,
Student_Answer_Text VARCHAR(255),
Satisfactory_YN CHAR(1),
Assessment VARCHAR(40),
PRIMARY KEY (Student_Answer_ID),
FOREIGN KEY (Valid_Answer_ID) REFERENCES Valid_Answers (Valid_Answer_ID)
);