text: DROP TABLE IF EXISTS product_groups;
  
  CREATE TABLE product_groups
  (
    id SERIAL PRIMARY KEY,
    name varchar(120) NOT NULL
  );
  
  DROP TABLE IF EXISTS products;
  
  CREATE TABLE products
  (
    id SERIAL PRIMARY KEY,
    name varchar(120) NOT NULL,
    description varchar(300) NOT NULL,
    price decimal(8,2),
    product_group_id integer,
     CONSTRAINT fk_product_group_id
        FOREIGN KEY(product_group_id) 
  	  REFERENCES product_groups(id)
  );
  
  INSERT INTO product_groups (name) VALUES ('Product Group 1');
  
  INSERT INTO product_groups (name) VALUES ('Product Group 2');