[postgis-users] Anti st_union

[Maxime van Noppen]

Bob Pawley wrote:
> Hi
>  
> In order to have only one row, I have a number of points  stored in a
> table as st_union.
>  
> Is there a method of breaking the points out of  the st_union geometry
> so that I can access the points individually.
>  
> I want to use the points as a reference for st_within. It doesn't seem
> to works as it seems to regard the st_union point geometry as a whole.

Hi,

That depends of the type of the resulting geometry. If it is a
MultiPoint (which it likely is if you ST_Union-ed points) you should
look at the ST_Dump function :

http://postgis.refractions.net/documentation/manual-1.4/ST_Dump.html

-- 
Maxime