On Mon, 27 Jul 2015 at 17:34, Marc L. Allen wrote:
> Sorry.. confused.... does sqlite allow comparison between NULLs?
No.
> LEFT JOIN work ON work.fpath = home.fpath WHERE work.fpath IS NULL
>
> Should never match anything... it checks to see if work.fpath IS
> NULL and if the same work.fpath is equal to something.
It is a LEFT (OUTER) join, which NULLs the columns of the right thable
in the result set for rows in the left table that don't have a match.
cu
Reinhard
