Currently, it's a WPS process - the code is at https://github.com/ianturton/tablejoin
It's built around a FilterVisitor that replaces join values with literals I think. Ian On Tue, 3 Nov 2020 at 19:25, Jim Hughes <jhug...@ccri.com> wrote: > Hi Ian, > > Interesting. Is the Joining datastore somewhere online already? > > I'll admit to having written similar datastores previously. One of my > ideas for using this kind of DataStore would be to leverage functions like > those in the GS Query Layer extension to pull attributes from other > layers. Similarly, it ought to be trivial to pull a column from a CSV on > disk. > > As one starts down that path, there are syntactical annoyances (I cannot > see an easy way to say "get a bunch of columns from other there" without > having a function call per column), and performance considerations (reading > from a file/database repeated for the same information among separate > queries is less than ideal, so caching would be nice). That said, in a > pinch, this approach may provide a really, really quick solution. > > Cheers, > > Jim > On 11/3/20 1:53 PM, Ian Turton wrote: > > This looks interesting, I wonder how hard it would be to merge in the work > I did on Joining datastores that could create "views" across non-jdbc > datastores so you could add a CSV to a geometry in another store, I should > dig that code out and look at it again. Maybe a christmas lockdown project? > > Ian > > On Tue, 3 Nov 2020 at 18:19, Jim Hughes <jhug...@ccri.com> wrote: > >> Hi all, >> >> At various times, Jody and I have chatted about having a "CQL View" in >> GeoServer (or something similar akin to the SQL Views) that'd leverage >> the Transform module and allow one to add columns to a FeatureSource >> based on expressions. Such expressions could use existing or custom CQL >> functions and that'd open a world of possibilities. >> >> Last week, I asked Jody about this idea again and he indicated that one >> would really just need to write a DataStoreFactory. I banged out an >> initial implementation as a starting place for the conversation. This >> implementation provides a way to project down to a subset of attributes >> as well as add new columns/attributes to a FeatureStore. >> >> If folks like it as-is, I'd be happy to add unit tests, and >> documentation wherever we see fit. Thanks in advance for some feedback >> on this idea! >> >> https://github.com/geotools/geotools/pull/3196/files >> >> Cheers, >> >> Jim >> >> >> >> _______________________________________________ >> GeoTools-Devel mailing list >> GeoTools-Devel@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/geotools-devel >> > > > -- > Ian Turton > > > -- Ian Turton
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