[Mapserver-users] Re: POSTGIS - subselect problem

[Alexandros Chimarios]

Solved this problem on my own. 
It is clearly mentioned in PostGIS manual that MapServer needs to have a 
unique id in each row in a subselect. Therefore I created an index on unit_id 
and I  added the unit_id column in the query  and worked.

DATA " geolocation from (SELECT geolocation, unit_id from unit_tracks) as foo 
using unique unit_id using srid=-1  "


Regards 

Alex



On Tuesday 27 April 2004 16:54, you wrote:
> Hello,
>
> I have a problem with POSTGIS and in particular with subselects. I have a
> POSTGIS layer and everything go well when i put :
>
> DATA " geolocation from  unit_tracks USING UNIQUE unit_id   USING SRID = -1
> "
>
>
> ... but when i put the following data(which theoritically is the same data
> with the previous one) I get a segmentation fault :
>
> DATA " geolocation from (SELECT geolocation from unit_tracks) as foo using
> unique oid using srid=-1  "
>
> Could anyone explain me what's happening here since subselecting is very
> important thing.
>
> Thanx
>
> Alexandros.