Yup, add any dummy element of any kind (since a collection can be mixed) and you have a work-around. You could instead bypass the query if the search collection is empty, that would be logical, might even be (insignificantly) more efficient <smirk>.
Keisuke mentions a potential issue about "runtime"… I've not tested this behavior when compiled. Left to ponder: is it a bug or a feature? Either way I'm not seeing it as "appropriate". > On Mar 3, 2020, at 3:57 AM, Adrian Boone via 4D_Tech <[email protected]> > wrote: > > That's exactly what I assumed - if the collection is empty, you'd expect that > "not in collection" would return everything, but in my experience (v17.1) it > returns nothing! The workaround I have for now is to add a dummy element to > the collection and that works as expected. In my case it's a collection of > UUIDs from another ORDA query, so I just add a garbage UUID, but I guess even > adding an empty string would do the trick? > > Adrian > > On 03/03/2020 08:52, Keisuke Miyako via 4D_Tech wrote: >> I do not have any insider knowledge on this particular point, >> but I would assume that the runtime simply ignores the instruction and >> return all entities if the collection is empty (length=0), >> since the condition is the inverse of a "false" statement. >> >> matching an empty string is a different equation. >> any string of any length that matches an empty string according to unicode >> collation for the current locale rules is a match. >> control characters, non characters, etc. that are not identical to "" can >> still be equivalent to "". >> such entities must be removed from the resulting entity selection in this >> case because of the "NOT". >> >>> On Mar 3, 2020, at 17:26, Douglas Cryer via 4D_Tech <[email protected]> >>> wrote: >>> >>> Re: >>> Why is my query of >>> NOT(IN []) >>> versus >>> NOT(IN [""]) >>> producing difference results? >> ********************************************************************** >> 4D Internet Users Group (4D iNUG) >> Archive: http://lists.4d.com/archives.html >> Options: https://lists.4d.com/mailman/options/4d_tech >> Unsub: mailto:[email protected] >> ********************************************************************** > > > ********************************************************************** > 4D Internet Users Group (4D iNUG) > Archive: http://lists.4d.com/archives.html > Options: https://lists.4d.com/mailman/options/4d_tech > Unsub: mailto:[email protected] > ********************************************************************** ********************************************************************** 4D Internet Users Group (4D iNUG) Archive: http://lists.4d.com/archives.html Options: https://lists.4d.com/mailman/options/4d_tech Unsub: mailto:[email protected] **********************************************************************
