ST_GeographyFromWKB

Converts a Well-Known Binary (WKB) value into its corresponding GEOGRAPHY object. Use this function to convert a WKB into the format expected by Vertica Place functions.

A GEOGRAPHY object is a spatial object defined on the surface of the earth. Coordinates are expressed in degrees (longitude, latitude) from reference planes dividing the earth. All calculations are in meters.

The maximum size of a GEOGRAPHY object is 10 MB. If you pass a WKB to ST_GeographyFromWKB that results in a spatial object whose size is greater than 10 MB, ST_GeographyFromWKB 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

Immutable

Syntax

ST_GeographyFromWKB( wkb [ USING PARAMETERS ignore_errors={'y'|'n'} ] )

Arguments

wkb

Well-Known Binary (WKB) value of a GEOGRAPHY object, type LONG VARBINARY

ignore_errors

(Optional) ST_GeographyFromWKB returns the following, based on the parameters supplied:

  • NULL—If wkb is invalid and ignore_errors='y'.
  • Error—If wkb is invalid and ignore_errors='n' or is unspecified.

Returns

GEOGRAPHY

Supported Data Types

Data Type GEOGRAPHY (Perfect Sphere) GEOGRAPHY (WGS84)
Point Yes Yes
Multipoint

Yes

Yes

Linestring

Yes

Yes

Multilinestring

Yes

Yes

Polygon

Yes

Yes

Multipolygon

Yes

Yes

GeometryCollection

No

No

Example

The following example shows how to use ST_GeographyFromWKB.

Convert WKB into a GEOGRAPHY object:

=> CREATE TABLE wkb_ex (g GEOGRAPHY);
CREATE TABLE
=> INSERT INTO wkb_ex VALUES(ST_GeographyFromWKB(X'0103000000010000000 ... );
 OUTPUT 
--------
      1
(1 row)