erDiagram
    Country ||--o{ StateProvince : "has"
    StateProvince ||--o{ City : "has"

    %% Cross-schema: defined in full in brewery.mmd
    City ||--o{ BreweryLocation : "located in"

    Country {
        uniqueidentifier CountryID PK
        nvarchar CountryName
        char ISO3166_1 UK
    }

    StateProvince {
        uniqueidentifier StateProvinceID PK
        nvarchar StateProvinceName
        char ISO3166_2 UK
        uniqueidentifier CountryID FK
    }

    %% CityName + StateProvinceID form a composite unique constraint (AK_CityStateProvince)
    City {
        uniqueidentifier CityID PK
        nvarchar CityName UK
        uniqueidentifier StateProvinceID FK,UK
    }