On Jan 22, 10:20 pm, Kirill Simonov <x...@gamma.dn.ua> wrote:
> On 01/22/2011 12:25 AM, rusi wrote:
>
> > On Jan 22, 2:45 am, "Clark C. Evans"<c...@clarkevans.com> wrote:
> >> Kirill Simonov and myself would like to introduce HTSQL, a novel
> >> approach to relational database access which is neither an ORM nor raw SQL.
> > :
> >> We're curious what you think.
>
> > Thanks -- looks interesting.
>
> > Given the claim htsql is higher level than sql I am interested in
> > bill-of-materials type (recursive) queries.
>
> Currently HTSQL does not support recursive queries. That said, it's
> certainly within the reach of HTSQL and I could sketch here how the
> support may look like:
>
> We add an operator `closure()` that, given a self-referential link
> `link`, produces a transitive closure `closure(link)` of the link.
>
> For example, take a table `program` with a link `program.part_of`. Then
> `program.closure(part_of)` is a plural link mapping a program to its
> super-programs, which you can use just like a regular plural link, for
> instance, in aggregate expressions.
>
> To return, for each program, a list of its super-programs:
>
> /program{code, /closure(part_of){code}}
>
> To return all sub-programs of a specific program 'xxx':
>
> /program?exists(closure(part_of).code='xxx')
>
> Compare that with
>
> /program{code, part_of.code}
> /program?part_of.code='xxx'
>
> I think it would be a modest improvement over a SQL alternative.
>
> I'm adding it to the roadmap right now, but don't hold your breath -- Q4
> this year or early next year is a realistic ETA. I expect the
> implementation to be at least moderately painful and, obviously, it
> could only work with those backends that support WITH RECURSIVE.
O well...
I was hoping for some some quick-queries (one-liners?) to probe
firefox's bookmarks (which are in sqlite)
--
http://mail.python.org/mailman/listinfo/python-list
