ST_GeomFromWKB
ST_GeomFromWKB constructs a geometry object from a hexadecimal well-known binary (WKB) representation of an input geometry.
ST_GeomFromWKB accepts 3DZ, 3DM, and 4D geometries written in WKB hexadecimal format.
Syntax
ST_GeomFromWKB(wkb_string)
ST_GeomFromWKB(wkb_string, srid)
Arguments
- wkb_string
-
A value of data type
VARCHAR
that is a hexadecimal WKB representation of a geometry. - srid
-
A value of data type
INTEGER
that is a spatial reference identifier (SRID). If an SRID value is provided, the returned geometry has this SRID value. Otherwise, the SRID value of the returned geometry is set to 0.
Return type
GEOMETRY
If wkb_string or srid is null, then null is returned.
If srid is negative, then null is returned.
If wkb_string is not valid, then an error is returned.
If srid is not valid, then an error is returned.
Examples
The following SQL constructs a polygon from a WKB value and returns the WKT representation of a polygon.
SELECT ST_AsText(ST_GeomFromWKB('01030000000100000005000000000000000000000000000000000000000000000000000000000000000000F03F000000000000F03F000000000000F03F000000000000F03F000000000000000000000000000000000000000000000000'));
st_astext
--------------------------------
POLYGON((0 0,0 1,1 1,1 0,0 0))