spatial-queries

CKAN DataStore has no PostGIS, so convert the radius to a lat/lon bounding box and filter server-side with CAST and BETWEEN in SQL. Then apply a Haversine distance filter client-side to keep only points within the exact radius.

Fetch station_information.json and station_status.json from the BIXI GBFS API, then sort stations by Haversine distance from the user's coordinates. Join with the status feed to report available bikes at the nearest stations.

Latitude and longitude fields are stored as text in CKAN DataStore, so numeric comparisons fail without casting. Use CAST("Latitude" AS FLOAT) in the WHERE clause and add IS NOT NULL checks for records missing coordinates.

A bounding box is a square, so corner results can exceed the intended radius and must be filtered client-side with Haversine. Also, some datasets use MTM8 projected coordinates that must be converted to WGS84 first, and crime coordinates are deliberately offset for privacy.

No, the CKAN DataStore backend does not include PostGIS, so spatial functions like ST_DWithin are unavailable. The supported approach is a bounding-box SQL filter followed by precise client-side distance calculation.