카테고리:: 지리 공간 함수

ST_ASEWKT¶

Given a value of type GEOGRAPHY or GEOMETRY, return the text (VARCHAR) representation of that value in EWKT (extended well-known text) format.

참고 항목:: ST_ASWKT

구문¶

ST_ASEWKT( <geography_or_geometry_expression> )

인자¶

geography_or_geometry_expression: The argument must be an expression of type GEOGRAPHY or GEOMETRY.

반환¶

VARCHAR입니다.

사용법 노트¶

For GEOGRAPHY objects, the SRID in the return value is always 4326. See the note on EWKT handling.
출력을 WKT 형식으로 반환하려면 대신 ST_ASWKT 를 사용하십시오.

예¶

GEOGRAPHY Examples¶

다음 예는 ST_ASEWKT 함수를 보여줍니다.

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_asewkt(g)
    from geospatial_table
    order by id;
+-----------------------------------------------+
| ST_ASEWKT(G)                                  |
|-----------------------------------------------|
| SRID=4326;POINT(-122.35 37.55)                |
| SRID=4326;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 that have different SRIDs.

CREATE OR REPLACE TABLE geometry_table (g GEOMETRY);
INSERT INTO geometry_table VALUES
  ('SRID=4326;POINT(-122.35 37.55)'),
  ('SRID=0;LINESTRING(0.75 0.75, -10 20)');

ALTER SESSION SET GEOMETRY_OUTPUT_FORMAT='EWKT';
SELECT ST_ASEWKT(g) FROM geometry_table;

+-------------------------------------+
| ST_ASEWKT(G)                        |
|-------------------------------------|
| SRID=4326;POINT(-122.35 37.55)      |
| SRID=0;LINESTRING(0.75 0.75,-10 20) |
+-------------------------------------+