ST_MultiPoint If the geometry-expression is of type ST_MultiPoint, returns the geometry-expression. If the geometry-expression is a geometry collection containing only points, returns a multipoint object containing the elements of the geometry-expression. If the geometry-expression is of type ST_Point then return a multi-point value containing one element, the geometry-expression. If the geometry-expression is the empty set, returns an empty set of type ST_MultiPoint. Otherwise, raises an exception condition.
Examples
Example 1 –
The following example returns the result MultiPoint EMPTY.