I am trying to change the geometry of a PostGIS db from multipoint to point and using this expressions works quite well
SELECT (ST_Dump(the_geom)).geom AS the_POINT_geom FROM MULTIPOINT_table;
But when trying to add this as new column via
ALTER TABLE your_table ADD COLUMN the_POINT_geom double precision; UPDATE your_table SET the_POINT_geom = (ST_Dump(geom)).geom;
this only causes an error:
set-returning functions are not allowed in UPDATE
Is there a way to add the point geometry as new column?