Re: Feasibility of postgis fields?
Hi thanks for the replies - I'm surprised this is the only way to do it as using the model api would seem neater. Have you encountered many problems separating out the geom fields like this (eg - not being searchable in admin / whatever)? Yes I'd be interested in an example of how custom sql is implemented within the model code thanks. So how are you injecting the data into the database? Sounds like you'd need to do it in 2 steps using this approach - 1) create the model instance and commit, then 2) execute a method on the model from your dataloader to manually update the geom field afterwards with custom sql. Thanks, Nick --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/django-users -~--~~~~--~~--~--~---
Re: Feasibility of postgis fields?
On 6/15/06, nick <[EMAIL PROTECTED]> wrote: > Hi - as a person investigating django for managing metadata that will > also have a spatial/gis component (lat/lon bounding boxes), would the > reccommended approach be to create a new field for use in my models? > Admittedly this would be specific to the postgres+postgis backend. > > I'd be looking to implement a basic a polygon datatype and at runtime > allowing for queries to search for intersections of these with > user-defined points. The postgres+postgis && operator acheives this in > simple sql: > > SELECT > ID, NAME > FROM ROADS_GEOM > WHERE > GEOM && GeomFromText('POLYGON((191232 243117,191232 243119,191234 > 243117,191232 243117))',-1); Hey Nick, I've been using Django successfully with PostgreSQL/PostGIS for more than a year on http://www.chicagocrime.org/ . What I do is deliberately *exclude* the "GEOM" field from being defined in the model (because it doesn't yet have a Python/Django field class), and I use custom SQL statements in model methods to do the queries I want to do. Django doesn't really care if the database defines columns that aren't in the model, as long as you don't try to insert/change into that undefined field with the Django database API -- so I'm exploiting that. So, yeah, it's totally possible and easy to do. I'd be happy to post sample model code if you're interested. Adrian -- Adrian Holovaty holovaty.com | djangoproject.com --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/django-users -~--~~~~--~~--~--~---
Re: Feasibility of postgis fields?
Hi Nick, On 6/15/06, nick <[EMAIL PROTECTED]> wrote: > Hi - as a person investigating django for managing metadata that will > also have a spatial/gis component (lat/lon bounding boxes), would the > reccommended approach be to create a new field for use in my models? > Admittedly this would be specific to the postgres+postgis backend. About custom fields I cannot tell you anything, but I recently helped the developer(s) of GeoTypes to release 0.6.0, which is also installable through CheeseShop/easy_install. I think this could be helpful providing you with the OpenGIS/PostGIS geometry types at least. See http://cheeseshop.python.org/pypi/GeoTypes/ -- Jeroen Ruigrok van der Werven --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/django-users -~--~~~~--~~--~--~---
Feasibility of postgis fields?
Hi - as a person investigating django for managing metadata that will also have a spatial/gis component (lat/lon bounding boxes), would the reccommended approach be to create a new field for use in my models? Admittedly this would be specific to the postgres+postgis backend. I'd be looking to implement a basic a polygon datatype and at runtime allowing for queries to search for intersections of these with user-defined points. The postgres+postgis && operator acheives this in simple sql: SELECT ID, NAME FROM ROADS_GEOM WHERE GEOM && GeomFromText('POLYGON((191232 243117,191232 243119,191234 243117,191232 243117))',-1); See http://postgis.refractions.net/docs/ Has anyone done this already and and I likely to run into any brick walls from the framework if I attempt to implement additional backend functionality through model fields? An aside, there seems to be no implementation of interfaces for the existing field types. Is this deliberate? Maybe I'm barking up the wrong tree if they're not meant to be extended. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/django-users -~--~~~~--~~--~--~---