ST_GeomFromGeoHash

ST_GeomFromGeoHash constructs a geometry object from the geohash representation of an input geometry. ST_GeomFromGeoHash returns a two-dimensional (2D) geometry with the spatial reference identifier (SRID) of zero (0). For more information about the geohash format, see Geohash in Wikipedia.

Syntax

ST_GeomFromGeoHash(geohash_string)

ST_GeomFromGeoHash(geohash_string, precision)

Arguments

geohash_string

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

precision

A value of data type INTEGER that represents the precision of the geohash. The value is the number of characters of the geohash to be used as precision. If the value is not specified, less than zero, or greater than the geohash_string length. then the geohash_string length is used.

Return type

GEOMETRY

If geohash_string is null, then null is returned.

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

Examples

The following SQL returns a polygon with high precision.

SELECT ST_AsText(ST_GeomFromGeoHash('9qqj7nmxncgyy4d0dbxqz0'));

 st_asewkt       
-----------------------
 POLYGON((-115.172816 36.114646,-115.172816 36.114646,-115.172816 36.114646,-115.172816 36.114646,-115.172816 36.114646))
 

The following SQL returns a point with high precision.

SELECT ST_AsText(ST_GeomFromGeoHash('9qqj7nmxncgyy4d0dbxqz00'));

 st_asewkt       
-----------------------
 POINT(-115.172816 36.114646)
 

The following SQL returns a polygon with low precision.

SELECT ST_AsText(ST_GeomFromGeoHash('9qq'));

 st_asewkt       
-----------------------
 POLYGON((-115.3125 35.15625,-115.3125 36.5625,-113.90625 36.5625,-113.90625 35.15625,-115.3125 35.15625))
 

The following SQL returns a polygon with precision 3.

SELECT ST_AsText(ST_GeomFromGeoHash('9qqj7nmxncgyy4d0dbxqz0', 3));

 st_asewkt       
-----------------------
 POLYGON((-115.3125 35.15625,-115.3125 36.5625,-113.90625 36.5625,-113.90625 35.15625,-115.3125 35.15625))