ST_ASWKT , ST_ASTEXT
Given a value of type GEOGRAPHY or GEOMETRY, return the
text (VARCHAR) representation of that value in
WKT (well-known text) format.
- See also:
ST_ASEWKT
Syntax
Use one of the following:
ST_ASWKT( <geography_or_geometry_expression> )
ST_ASTEXT( <geography_or_geometry_expression> )
Arguments
geography_or_geometry_expressionThe argument must be an expression of type GEOGRAPHY or GEOMETRY.
Examples
GEOGRAPHY examples
The following example demonstrates the ST_ASWKT function:
create table geospatial_table (id INTEGER, g GEOGRAPHY);
insert into geospatial_table values
(1, 'POINT(-122.35 37.55)'), (2, 'LINESTRING(-124.20 42.00, -120.01 41.99)');
select st_astext(g)
from geospatial_table
order by id;
+-------------------------------------+
| ST_ASTEXT(G) |
|-------------------------------------|
| POINT(-122.35 37.55) |
| LINESTRING(-124.2 42,-120.01 41.99) |
+-------------------------------------+
select st_aswkt(g)
from geospatial_table
order by id;
+-------------------------------------+
| ST_ASWKT(G) |
|-------------------------------------|
| POINT(-122.35 37.55) |
| LINESTRING(-124.2 42,-120.01 41.99) |
+-------------------------------------+
GEOMETRY examples
The example below demonstrates how to use the ST_ASEWKT function. The example returns the EWKT representations of two geometries.
CREATE OR REPLACE TABLE geometry_table (g GEOMETRY);
INSERT INTO geometry_table VALUES
('POINT(-122.35 37.55)'), ('LINESTRING(0.75 0.75, -10 20)');
ALTER SESSION SET GEOMETRY_OUTPUT_FORMAT='WKT';
SELECT ST_ASWKT(g) FROM geometry_table;
+------------------------------+
| ST_ASWKT(G) |
|------------------------------|
| POINT(-122.35 37.55) |
| LINESTRING(0.75 0.75,-10 20) |
+------------------------------+