[postgis-users] overall bbox from some polygons

[Samson, Marko]

Hi,

I want to get an overall-bbox of some polygons with a select statement.
With "select envelope(the_geom)from polygontable where oid in (.....)" I
just get the separate geoms of every single polygon. Now I'm looking for
a solution to get the bbox of all these polygons.
Is there a function or other elegant way to get the 'overall envelope'
of some polygons, or do I have to create a little sorting function into
my phpscript

Bye,
Marko