Stephane Fellah wrote: > > Hi, > > > > The WFS specification clearly specifies that aliases can be used in > the typeName attribute of the GetFeature request. However the OGC > Filter specification remains completely silent about how the usage of > aliases in the OGC Filter. So I went back to Peter Vretanos to ask > clarifications about this. Here an extract from what he sent to me > that I want to share with you in order to enhance to alias support > (useful for joins in query) in the Geotools. > Thanks for the background, would love to know: a) which version of WFS you are thinking of? Currently we only have a WFS 1.0 implementation based on geotools b) if WFS has made any progress on defining joins in a query?
My working understanding is this: - joins may be considered in light of the CAT 2 practice of having more then one filter per query - WFS 1.0 and WFS 1.1 do not support joins - geotools 2.2.x does not have an implementation of XPath that supports anything beyond "name" For a JXPath based geotools implementation look into the Feature Model branch, or complex-feature branch. Currently we lack anyone with time/budget to bring this work home promptly - but are pressing ahead slowly regardless. I do have a design capable of doing joins that is one of my writing projects, but I am not really interested until the feature model comes home. To answer your questions: > > Does Geotools supports aliases in the typename ? > no > > Does the different plugins such as Oracle Spatial, MYSQL,ArcSDE > leverage these capabilities ? no Right now the geotools community is focused on bringing some of the RnD branches home, namely a Grid Covearge branch and the above mentioned feature model branch. We may be able to look into what support JXPath has for alias, probably something that happens out of the box. Jody _______________________________________________ Geotools-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/geotools-devel
