That is correct - I am looking for records that are empty. I tried this version of the SQL query as well and during my testing, the first example seemed to be more efficient.
Also, I have version 3.8.10.2 on my home PC and version 3.6.20 on my server at work. I am going to update the server version and see if that makes a difference. On Mon, Jul 27, 2015 at 10:04 AM, Igor Tandetnik <igor at tandetnik.org> wrote: > On 7/27/2015 9:58 AM, Simon Slavin wrote: > >> So you're checking both to see that [work.fpath = home.fpath ] and to see >> that [work.fpath IS NULL]. This looks weird to me. >> > > That's a common technique with LEFT JOIN - it's selecting home records > that lack a corresponding work record. In other words, it's equivalent to > > SELECT fpath > FROM home > WHERE fpath NOT IN (SELECT fpath FROM work) > AND home.ftype = 'f?; > > -- > Igor Tandetnik > > _______________________________________________ > sqlite-users mailing list > sqlite-users at mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users >
