CREATE  TABLE users (
  id int(10) auto_increment primary key,
  username VARCHAR(45) NOT NULL ,
  password VARCHAR(45) NOT NULL ,
  enabled TINYINT NOT NULL DEFAULT 1
);

CREATE TABLE questions (
    id int(10) auto_increment primary key,
    question varchar(800) NOT NULL,
    right_option int(10) NOT NULL references options(id)
);

CREATE TABLE options (
    id int(10) auto_increment primary key,
    question_id int(10) NOT NULL references questions(id),
    `option` varchar(150) NOT NULL
);

CREATE TABLE exam_details (
    id int(10) auto_increment primary key,
    username varchar(45) NOT NULL references users(username),
    date_of_exam date not null,
    exam_result varchar(10) NOT NULL, -- PASS/FAIL
    exam_score int(10) NOT NULL,      -- e.g. 40 
    no_of_questions int(10) NOT NULL  -- total no. of questions in the test
);     

CREATE TABLE user_answers (
    id int(10) auto_increment primary key,
    userId int(10) NOT NULL references users(id),
    question_id int(10) NOT NULL references questions(id),
    answer int(10) NOT NULL references options(id)
);