ST_DWithin

Introduction: Tests whether two geographies are within a given geodesic distance (in meters) of each other on the sphere. The minimum great-circle distance between any two points on the two geographies is compared against the threshold; the test is inclusive (returns true when the minimum distance equals the threshold).

ST_DWithin returning true ST_DWithin returning false

Format:

ST_DWithin (A: Geography, B: Geography, distance: Double)

Return type: Boolean

Since: v1.9.1

SQL Example

SELECT ST_DWithin(
  ST_GeogFromWKT('POINT (0 0)', 4326),
  ST_GeogFromWKT('POINT (0 1)', 4326),
  200000.0
);

Output:

true

The same pair of points with a tighter threshold:

SELECT ST_DWithin(
  ST_GeogFromWKT('POINT (0 0)', 4326),
  ST_GeogFromWKT('POINT (0 1)', 4326),
  100000.0
);

Output:

false