[QGIS-Developer] Inconsistency between Query builder and Select by query dialogs

[Andreas Neumann]

Hi Paolo,

I asked the same question, but apparently there are technical reasons.

The Query builder creates a query that a data source can understand 
(e.g. OGR) - data is filtered at its source.

Whereas the expression builder is much, much richer and can't be 
translated to filters of data providers. Thus, such data filtering can 
only be done in the client - means that all features are requested from 
the source and then filtered client side.

I don't know if it would be technically possible to restrict the 
expression builder to a subset that a data provider can understand - so 
that the user can have just one interface, both with a limited set of 
operators and functions.

Andreas


On 15.09.2017 18:03, Paolo Cavallini wrote:
> Hi all,
> the two dialogs are quite different, whereas they do essentialy the same
> thing. Questions:
> * is there a specific reason why the Query builder has not been updated,
> or is it just the usual lack of time?
> * is anyone planning to work on this?
> Thanks.
>
>
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