Domain 2 — Geographic Data
provinces / cities / districts [CORE]/[MVP]
Role: The geo hierarchy backing service areas, addresses, and search. Why a table, not a static list: new cities/districts launch without a deploy, and sort_order/is_active drive ordered, toggleable dropdowns. districts map to Tehran's 22 municipal districts or major neighborhoods elsewhere; they are optional (a nurse can cover a whole city). Fields unchanged. Relations: provinces 1:N cities 1:N districts; referenced by customer_addresses and nurse_service_areas.
nurse_service_areas [CORE]
Role: Where a nurse will travel. A row with district_id = NULL means the entire city. Why a join table (not a radius): Iranian nurses think in named districts, not GPS radii; this also drives the geographic filter in search cheaply. Unchanged, with UNIQUE(nurse_id, city_id, district_id). Relations: N:1 → nurse_profiles, cities, districts.