wat.sql

create table countries (
  country             text      not null unique,
  country_code        char(2)   not null unique
);

create table country_areas (
  country_area        text      not null,
  country             text      not null references countries(country) on update cascade,
  unique              (country_area, country)
);

create table country_subareas (
  country_subarea     text      not null,
  country_area        text      not null references country_areas(country_area, country) on update cascade,
  country             text      not null references countries(country) on update cascade,
  unique              (country_subarea, country_area, country)
);

create table cities (
  city                text      not null,
  country_area        text      references country_areas(country_area, country) on update cascade,
  country_subarea     text      references country_subareas(country_subarea, country_area, country) on update cascade
  country             text      not null references countries(country) on update cascade,
  unique              (city, country, country_area, country_subarea)
);

create table postal_codes (
  postal_code         text      not null,
  city                text      not null references cities(city, country_subarea, country_area, country) on update cascade,
  country_area        text      not null references country_areas(country_area, country) on update cascade,
  country_subarea     text      not null references country_subareas(country_subarea, country_area, country) on update cascade
  country             text      not null references countries(country) on update cascade,
  unique              (postal_code, city, country_area, country_subarea, country)
);

create table customers (
  customer_id         uuid      primary key default uuid_generate_v4(),
  name                text,
  street              text,
  street2             text,
  postal_code         text      references postal_codes(postal_code, city, country_subarea, country_area, country) on update cascade,
  city                text      references cities(city, country_subarea, country_area, country) on update cascade,
  country_area        text      references country_areas(country_area, country) on update cascade,
  country_subarea     text      references country_subareas(country_subarea, country_area, country) on update cascade
  country             text      references countries(country) on update cascade
);