[Qgis-developer] Filter layer after join, error/impossible

[Hugo Mercier]

Hi Pierre,

Le 20/02/2015 16:31, PIERRE Sylvain a écrit :
> Hi,
> 
>  
> 
> I’ve same behaviour with different case :
> 
> I want to filter a layer (Oracle/Postgis) after performing join with
> tabular data (Excel, MSSQL tested).
> 
> First Filtering by Layer properties Ui is disabled (greyed button)
> 
> Filtering possible by Menu “Layer”-“Filter”
> 
> Joined fields appears, and Sample values do so.
> 
> But when I want to test filter I got an error message box: (sorry in French)
> 
> “Une erreur a été rencontrée lors de l'exécution de la requête.
> 
> Le prestataire de donné a dit :
> 
> ORA-00904: "V_SIG_SITE_Site_Nature" : identificateur non valide
> 
> Impossible d'exécuter cette déclaration »
> 
>  

The filtering of a layer is done at the provider level, where nothing is
known about the joined fields (they only exist QGIS side).

I've submitted a patch (1) to fix the UI issues: we will be able to
filter on layers with joined fields, but only on fields of the primary
table.
If you need to filter on joined fields, I am working on a "virtual
layer" provider where you could use any SQL joins. A small function
would allow to convert a layer with joins to a virtual layer and apply
filtering on it.
More on this next week, hopefully ...

(1) https://github.com/qgis/QGIS/pull/1911