ST_GeomFromGeoJSON

ST_GeomFromGeoJSON constructs a geometry object from the GeoJSON representation of an input geometry. For more information about the GeoJSON format, see GeoJSON in Wikipedia.

If there is at least one point with three or more coordinates, the resulting geometry is 3DZ, where the Z component is zero for the points that have only two coordinates. If all points in the input GeoJSON contain two coordinates or are empty, ST_GeomFromGeoJSON returns a 2D geometry. The returned geometry always has the spatial reference identifier (SRID) of 4326.

Syntax

ST_GeomFromGeoJSON(geojson_string)

Arguments

geojson_string

A value of data type VARCHAR or an expression that evaluates to a VARCHAR type, that is a GeoJSON representation of a geometry.

Return type

GEOMETRY

If geojson_string is null, then null is returned.

If geojson_string is not valid, then an error is returned.

Examples

The following SQL returns a 2D geometry represented in the input GeoJSON.

SELECT ST_AsEWKT(ST_GeomFromGeoJSON('{"type":"Point","coordinates":[1,2]}'));

 st_asewkt       
-----------------------
 SRID=4326;POINT(1 2)
 

The following SQL returns a 3DZ geometry represented in the input GeoJSON.

SELECT ST_AsEWKT(ST_GeomFromGeoJSON('{"type":"LineString","coordinates":[[1,2,3],[4,5,6],[7,8,9]]}'));

 st_asewkt  
------------------------------------------
 SRID=4326;LINESTRING Z (1 2 3,4 5 6,7 8 9)
 

The following SQL returns 3DZ geometry when only one point has three coordinates while all other points have two coordinates in the input GeoJSON.

SELECT ST_AsEWKT(ST_GeomFromGeoJSON('{"type":"Polygon","coordinates":[[[0, 0],[0, 1, 8],[1, 0],[0, 0]]]}'));

 st_asewkt  
------------------------------------------------
 SRID=4326;POLYGON Z ((0 0 0,0 1 8,1 0 0,0 0 0))