text: CREATE TABLE IF NOT EXISTS category (
    id SERIAL,
    name VARCHAR(45) NOT NULL UNIQUE,
    PRIMARY KEY (id)
  );
  
  CREATE TABLE IF NOT EXISTS question (
    id SERIAL,
    category_id INTEGER,
    text VARCHAR(45) NOT NULL,
    PRIMARY KEY (id),
    FOREIGN KEY (category_id) REFERENCES category(id)
  );
  
  CREATE TABLE IF NOT EXISTS answer (
    id SERIAL,
    question_id INTEGER,
    text VARCHAR(45) NOT NULL,
    is_correct BOOLEAN,
    PRIMARY KEY (id),
    FOREIGN KEY (question_id) REFERENCES question(id)
  );
  