Re: [back-sql] Problem with NOT search requests (ITS#2652)

[ando@sys-net.it]

> Full_Name: Emmanuel Duru
> Version: 2.2.0 alpha
> OS: solaris 8
> URL:
> Submission from: (NULL) (195.68.44.148)
>
>
> A search request like (!<some attribute>=<some value>) should select the
> entries which do not have <some attribute>; with back-sql only entries
> which have at least one value for <some attribute> are selected. The
> problem is that the request to select candidate entries perform a join
> on the attribute in the filter (excluding entries without the
> attribute). Consequently, the search request (!<some attribute>=*) does
> not select any entry.
> [Pierangelo Masarati] This is a known limitation caused by the design of
> the backend;
> some filters may not generate complete queries.  We might need
> to think about a different design, if feasible.

I don't think this problem can be easily overcome.
I can easily figure out a simple query that does this
if the filter is of the type (!<ava>); if the filter
is (!<complex filter>) things get much more involved.
We might have to live with it.

p.


-- 
Pierangelo Masarati
mailto:pierangelo.masarati@sys-net.it