Table: network_system

Description (EN): This table represents infrastructural network systems (e.g., transport, electrical, or telecommunication grids). In the database's inheritance architecture, it acts as a direct sub-type of the enterprise table. It does not store redundant descriptive columns; instead, it uses a shared primary key to inherit all high-level attributes (such as name, location, management type, and geometry) from its parent enterprise record.

Column Structure

Column	Data type	Definition	Example value	Constraint?	Geometry?	Comments
id	BIGINT	Unique identifier for the network system	8	PK, FK	No	Primary key that also acts as a Foreign Key referencing enterprise.id

Relationships

• Inherits from (Sub-type of): enterprise. The network_system table is a specialized extension of the enterprise table.
• Contains: While not linked directly via a network_system_id, a network system owns infrastructural assets through the enterprise_id column in the component table. These components often include specialized sub-types such as:
  • transport_network_component
  • electrical_network_component
  • tlc_network_component
  • network_service

!!! tip "Where is the rest of the data?" To find the name, geographical location (geometry, town, country), or ownership details of a network system, you must join this table with the enterprise record that shares the exact same id.

Example Query

Retrieve a list of all network systems, including their names, towns, and spatial coordinates, by joining the table with its parent enterprise entity:

SELECT 
    n.id, 
    e.name, 
    e.town, 
    ST_AsText(e.geometry) as coordinates 
FROM 
    network_system n
JOIN 
    enterprise e ON n.id = e.id
WHERE 
    e.type = 'NETWORK_SYSTEM';