postgis使用wkt或wkb創建幾何

• 使用wkt創建 ST_GeomFromText
• 使用wkb創建 ST_GeomFromWKB
• 導出爲wkt ST_AsText
• 導出爲wkb ST_AsEWKB

postgres=# select ST_AsEWKB(ST_GeomFromWKB ('\x0101000020e6100000dfc0e44691145d40e355d636c5fb4340', 4326 ));
警告:  OGC WKB expected, EWKB provided - use GeometryFromEWKB() for this
                      st_asewkb
------------------------------------------------------
 \x0101000020e6100000dfc0e44691145d40e355d636c5fb4340
(1 行記錄)


postgres=# select ST_AsText(ST_GeomFromWKB ('\x0101000020e6100000dfc0e44691145d40e355d636c5fb4340', 4326 ));
警告:  OGC WKB expected, EWKB provided - use GeometryFromEWKB() for this
          st_astext
-----------------------------
 POINT(116.321367 39.966956)
(1 行記錄)


postgres=# select ST_AsEWKB(ST_GeomFromText ('POINT(116.321367 39.966956)', 4326 ));
                      st_asewkb
------------------------------------------------------
 \x0101000020e6100000dfc0e44691145d40e355d636c5fb4340
(1 行記錄)


postgres=# select ST_AsText(ST_GeomFromText ('POINT(116.321367 39.966956)', 4326 ));
          st_astext
-----------------------------
 POINT(116.321367 39.966956)