Categories:: Geospatial functions, Conversion functions

ST_GEOGRAPHYFROMWKT¶

Parses a WKT (well-known text) or EWKT (extended well-known text) input and returns a value of type GEOGRAPHY.

Aliases:: ST_GEOGFROMWKT , ST_GEOGRAPHYFROMEWKT , ST_GEOGFROMEWKT , ST_GEOGRAPHYFROMTEXT , ST_GEOGFROMTEXT
See also:: TO_GEOGRAPHY

Syntax¶

ST_GEOGRAPHYFROMWKT( <varchar_expression> [ , <allow_invalid> ] )

ST_GEOGFROMWKT( <varchar_expression> [ , <allow_invalid> ] )

ST_GEOGRAPHYFROMEWKT( <varchar_expression> [ , <allow_invalid> ] )

ST_GEOGFROMEWKT( <varchar_expression> [ , <allow_invalid> ] )

ST_GEOGRAPHYFROMTEXT( <varchar_expression> [ , <allow_invalid> ] )

ST_GEOGFROMTEXT( <varchar_expression> [ , <allow_invalid> ] )

Arguments¶

Required:

varchar_expression: The argument must be a string expression in WKT or EWKT that represents a valid geospatial object.

Optional:

allow_invalid: If TRUE, specifies that the function returns a GEOGRAPHY or GEOMETRY object, even when the input shape isn’t valid and can’t be repaired. For more information, see Specifying how invalid geospatial shapes are handled.

Returns¶

The function returns a value of type GEOGRAPHY.

Usage notes¶

Issues an error if the input cannot be parsed as WKT or EWKT.
Issues an error if the input format is EWKT and the SRID is not 4326. See the note on EWKT and EWKB handling.

For the coordinates in WKT, EWKT, and GeoJSON, longitude appears before latitude (for example, POINT(lon lat)).

Examples¶

The following example returns the GEOGRAPHY object for a geospatial object described in WKT format:

-- Set the output format to WKT
alter session set GEOGRAPHY_OUTPUT_FORMAT='WKT';

select ST_GEOGRAPHYFROMWKT('POINT(-122.35 37.55)');

+---------------------------------------------+
| ST_GEOGRAPHYFROMWKT('POINT(-122.35 37.55)') |
|---------------------------------------------|
| POINT(-122.35 37.55)                        |
+---------------------------------------------+

The following example returns the GEOGRAPHY object for a geospatial object with a Z coordinate described in WKT format:

-- Set the output format to WKT
alter session set GEOGRAPHY_OUTPUT_FORMAT='WKT';

select ST_GEOGRAPHYFROMWKT('POINTZ(-122.35 37.55 30)');

+-------------------------------------------------+
| ST_GEOGRAPHYFROMWKT('POINTZ(-122.35 37.55 30)') |
|-------------------------------------------------|
| POINTZ(-122.35 37.55 30)                        |
+-------------------------------------------------+

The following example returns the GEOGRAPHY object for a geospatial object described in EWKT format:

-- Set the output format to EWKT
alter session set GEOGRAPHY_OUTPUT_FORMAT='EWKT';

select ST_GEOGRAPHYFROMEWKT('SRID=4326;POINT(-122.35 37.55)');

+--------------------------------------------------------+
| ST_GEOGRAPHYFROMEWKT('SRID=4326;POINT(-122.35 37.55)') |
|--------------------------------------------------------|
| SRID=4326;POINT(-122.35 37.55)                         |
+--------------------------------------------------------+