ST_GeomFromWKB
Converts the Well-Known Binary (WKB) value to its corresponding GEOMETRY object. Use this function to convert a WKB into the format expected by many of the Vertica Place functions.
A GEOMETRY object is a spatial object with coordinates (x,y) defined in the Cartesian plane.
The maximum size of a GEOMETRY object is 10 MB. If you pass a WKB to ST_GeomFromWKB
and the result is a spatial object whose size is greater than 10 MB, ST_GeomFromWKB
returns an error.
The Open Geospatial Consortium (OGC) defines the format of a WKB representation in section 8 in the Simple Feature Access Part 1 - Common Architecture specification.
Behavior type
ImmutableSyntax
ST_GeomFromWKB( wkb[, srid] [ USING PARAMETERS ignore_errors={'y'|'n'} ])
Arguments
wkb
- Well-Known Binary (WKB) value of a GEOMETRY object, type LONG VARBINARY
srid
- (Optional) Spatial reference system identifier (SRID) of the GEOMETRY object, type INTEGER.
The SRID is stored in the GEOMETRY object, but does not influence the results of spatial computations.
ignore_errors
- (Optional)
ST_GeomFromWKB
returns the following, based on the parameters supplied:-
NULL—If
wkb
is invalid andignore_errors
='y'
. -
Error—If
wkb
is invalid andignore_errors
='n'
or is unspecified.
-
Returns
GEOMETRY
Supported data types
Data Type | GEOMETRY |
---|---|
Point | Yes |
Multipoint | Yes |
Linestring | Yes |
Multilinestring | Yes |
Polygon | Yes |
Multipolygon | Yes |
GeometryCollection | Yes |
Examples
The following example shows how to use ST_GeomFromWKB.
Convert GEOMETRY into WKT:
=> CREATE TABLE t(g GEOMETRY);
CREATE TABLE
=> INSERT INTO t VALUES(
ST_GeomFromWKB(X'0103000000010000000400000000000000000000000000000000000000000000000000f
03f0000000000000000f64ae1c7022db544000000000000f03f00000000000000000000000000000000'));
OUTPUT
--------
1
(1 row)
=> SELECT ST_AsText(g) from t;
ST_AsText
------------------------------------
POLYGON ((0 0, 1 0, 1e+23 1, 0 0))
(1 row)