text: CREATE TABLE transmission (
  	id SERIAL PRIMARY KEY,
  	type VARCHAR(20) NOT NULL,
  	vendor VARCHAR(20) NOT NULL
  	);
  	
  CREATE TABLE engine (
  	id SERIAL PRIMARY KEY,
  	type VARCHAR(20) NOT NULL,
  	vendor VARCHAR(20) NOT NULL
  	);
  	
  CREATE TABLE gearbox (
  	id SERIAL PRIMARY KEY,
  	type VARCHAR(20) NOT NULL,
  	vendor VARCHAR(20) NOT NULL
  	);
  	
  CREATE TABLE automobile (
  	id SERIAL PRIMARY KEY,
  	type VARCHAR(20) NOT NULL,
  	vendor VARCHAR(20) NOT NULL,
  	transm_id INTEGER UNIQUE REFERENCES transmission(id) NOT NULL,
  	engine_id INTEGER UNIQUE REFERENCES engine(id) NOT NULL,
  	gear_id INTEGER UNIQUE REFERENCES gearbox(id) NOT NULL
  	);