ST_PointFromText — Makes a point Geometry from WKT with the given SRID. If SRID is not given, it defaults to unknown.
geometry ST_PointFromText(text WKT
geometry ST_PointFromText(text WKT, integer srid
Constructs a PostGIS ST_Geometry point object from the OGC Well-Known text representation. If SRID is not given, it defaults to unknown (currently 0). If geometry is not a WKT point representation, returns null. If completely invalid WKT, then throws an error.
There are 2 variants of ST_PointFromText function, the first takes no SRID and returns a geometry with no defined spatial reference system. The second takes a spatial reference id as the second argument and returns an ST_Geometry that includes this srid as part of its meta-data. The srid must be defined in the spatial_ref_sys table.
If you are absolutely sure all your WKT geometries are points, don't use this function. It is slower than ST_GeomFromText since it adds an additional validation step. If you are building points from long lat coordinates and care more about performance and accuracy than OGC compliance, use ST_MakePoint or OGC compliant alias ST_Point.
This method implements the OpenGIS Simple Features Implementation Specification for SQL 1.1. s188.8.131.52 - option SRID is from the conformance suite.
This method implements the SQL/MM specification. SQL-MM 3: 6.1.8
SELECT ST_PointFromText('POINT(-71.064544 42.28787)'); SELECT ST_PointFromText('POINT(-71.064544 42.28787)', 4326);