[postgis-users] ST_UNION / Make a big polygon from some others

[Frank Durstewitz, Emporis GmbH]

Hi.

Not sure how to do ST_UNION, for creating i.e. the outer borders for 
continents from the country borders.
I have the country borders, and i have a field to which continent the 
country belongs.

SELECT ST_Union(the_geom)
FROM world_level_1
GROUP BY continentid

for sure doesn't work...

Anybody?

Kindly regards, Frank