Locationwhere

Locationwhere is a term used in discussions of geospatial data to describe a hypothetical operator that combines location constraints with data filtering, effectively merging a geographic predicate with a query’s where clause. It is not a standardized feature in major database systems, but the idea resembles how spatial predicates are applied in practice.

The concept parallels the use of spatial predicates such as within, contains, or distance-based checks in geospatial extensions to SQL. In many systems, location-based filtering is implemented by placing a spatial predicate in the WHERE clause, for example filtering rows by whether a geometry lies inside a given area or within a certain distance of a point.

In a hypothetical implementation, locationwhere would allow a single clause to express both a spatial condition and other non-spatial filters. Example: SELECT id, name FROM places LOCATIONWHERE within(geom, 'POLYGON((...))') AND type = 'park'. Many real systems achieve similar results with standard SQL using spatial predicates, such as SELECT id, name FROM places WHERE ST_Within(geom, ST_GeomFromText('POLYGON((...))', 4326)) AND type = 'park'.

Applications for locationwhere concepts include urban planning, logistics, and location-based services, where combining geographic constraints with other filters can streamline queries. Limitations include a lack of standardization across platforms, potential vendor dependence, and the need for appropriate spatial indexing to ensure performance.

Related concepts include geospatial databases, spatial indexes, and data formats such as GeoJSON and Well-Known Text (WKT).