text: create table states (
      id  bigserial not null,
      name varchar(255),
      country_id int8 not null,
      primary key (id)
  );
  
  alter table states
      add constraint uk_state_name unique (name);
  
  alter table states
      add constraint FKskkdphjml9vjlrqn4m5hi251y
      foreign key (country_id)
      references countries;
  