[Qgis-user] Qgis, postgis and updateable views

[Rob Marjot]

Hi Ricardo,

I am planning to do sort of the same thing in the near future... Any
progress? Keep us updated!

Sorry I'm not of any help... What you could try: how do other GIS packages
interact with your updatable view?


Rob

2009/10/24 Ricardo Filipe Soares Garcia da <ricardo.garcia.silva at gmail.com>

> Hello list
> I am using Qgis 1.3.0 compiled from the release tarball on Kubuntu 9.04.
>
> I am trying to create an updateable postgis view that will be updated
> through Qgis.
>
> I have a postgis DB with spatial and non-spatial tables. I'm using a
> view to abstract the relational connections between several tables and
> a spatial table and present the user (me) with a flat-file-like type
> of visualization through Qgis, so that I can see the real values of my
> spatial data instead of a bunch of foreign keys. This visualization is
> working fine, I have created the postgis view and can use it inside
> Qgis.
>
> Now I'd like to be able to use Qgis to insert and update my view and
> have postgresql do the real inserting and updating to my tables in the
> background. For this purpose I am creating some postgresql rules as in
> shown in [1] and [2]. So far I have succeeded in creating the UPDATE
> rule, which is working really nice and I think I have successfully
> created the INSERT rule as well, but I'm unable to test it due to Qgis
> crashing.
>
> My problem lies with the creation of new geometries.
> So far Qgis is crashing with the 'Segmentation fault' message when I
> try to create a new polygon on the view layer:
> To replicate the crash:
>    1 - load postgis layer (this layer is a postgis view, definded
> with SQL code in [3]) in Qgis
>    2 - toggle the edit mode to 'on'
>    3 - select the 'capture polygon' tool
>    4 - click anywhere on the map canvas
>    5 - ugly crash (segmentation fault reported on the console)
>
> Is it not possible to draw a new feature on a view layer? can someone
> replicate this behaviour? If not, it really should because the insert
> rule on postgres's side will (hopefully and most likely) accept that.
> Please note than I can update an already existing feature (for example
> moving some vertices around) and it works ok.
>
> Thanks in advance
>
> [1] -
> http://www.postgresonline.com/journal/index.php?/archives/11-Database-Abstraction-with-Updateable-Views.html
> [2] - http://www.postgresql.org/docs/8.1/interactive/rules-update.html
> [3] - SQL code follows:
>
> CREATE OR REPLACE VIEW salasp1 AS
>        SELECT s.sa_gid, s.the_geom,
>                e.sigla AS edificio, p.numero AS piso,
>                s.nome AS sala, t.tipo, f.funcionalidade,
>                d.sigla AS sigla_dep_servico, d.nome AS dep_servico,
>                s.descricao, s.lugares, s.tomadas, s.telefones
>        FROM sala s, tipo t, funcionalidade f, piso p, edificio e,
> deptoservico d
>        WHERE p.numero=1 AND p.pi_gid=s.pi_gid
>                AND s.ti_id=t.ti_id AND s.fu_id=f.fu_id
>                AND e.sigla='C8' AND d.dep_id=s.depserv_id;
>
>
> --
> ___________________________ ___ __
> Ricardo Garcia Silva
> _______________________________________________
> Qgis-user mailing list
> Qgis-user at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/qgis-user
>
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