ST_Point If the geometry-expression is of type ST_Point, return the geometry-expression. If the geometry-expression is a geometry collection with a single element of type ST_Point, return that element. If the geometry-expression is the empty set, return an empty set of type ST_Point. Otherwise, raise an exception condition.
Examples
Example 1 –
The following example returns the result Point (1 2).
SELECT NEW ST_GeomCollection( NEW ST_Point(1,2) ).ST_ToPoint()