PostGIS space function

1.ST_AsText（）

Convert spatial data （geom type ） Display as text

2.ST_GeomFromGeoJSON（）

take geojson Format data is converted into spatial data （geom type ）

SELECT ST_AsText(ST_GeomFromGeoJSON('{"coordinates":[[[506725.4551631873,2492636.8135885904],[505878.7868031839,2487462.7288792557],[513216.58097909775,2488497.546337888],[513310.6529445854,2493671.6310472228]]],"type":"Polygon"}'))

3.ST_GeometryFromText()

take wkt Format text data into spatial data （geom type ）

SELECT ST_AsText(ST_GeometryFromText('POLYGON((117.083114730229 22.5607317467891,117.082720462537 22.5607646218051,117.08269342201 22.5604848493124,117.082238586205 22.560524508964,117.082193809566 22.5600594071482,117.083049766267 22.559990716164,117.083114730229 22.5607317467891))'))

4.ST_Transform（）

Coordinate conversion function

SELECT ST_AsText(ST_Transform(st_geometryfromtext('POLYGON((117.083114730229 22.5607317467891,117.082720462537 22.5607646218051,117.08269342201 22.5604848493124,117.082238586205 22.560524508964,117.082193809566 22.5600594071482,117.083049766267 22.559990716164,117.083114730229 22.5607317467891))',4326),2384))