Hi all, For reference I wrote about this here: https://gis.stackexchange.com/a/212398
A small addition to Andreas' statement "filtering can only be done on the client", this is no longer entirely the case, a lot of standard SQL can already be translated and sent to the backend. It would be possible to adjust the "query builder" - also known as subsetString - to also work with QgsExpressions. Pro: increased portability between providers and better "QGIS standard" compatibility with things like support for variables and python expression functions Con: less integration with what some providers (mostly databases) offer natively (some advanced SQL) I think there is a need for both, so I could also imagine a radio button to switch between the two. Matthias On 9/15/17 6:26 PM, Andreas Neumann wrote: > > 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. >> >> >> _______________________________________________ >> QGIS-Developer mailing list >> [email protected] >> List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer >> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer > > > > _______________________________________________ > QGIS-Developer mailing list > [email protected] > List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer
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