[DB-SIG] A slightly different paramstyle suggestion

[Anthony Tuininga]

On 6/22/07, Carsten Haese <carsten at uniqsys.com> wrote:
> On Thu, 2007-06-21 at 10:33 -0600, Anthony Tuininga wrote:
> > I would like to suggest adding
> > the syntactic sugar (*args, *kwargs) in order to avoid having to build
> > the list, tuple or dictionary when passing arguments to the execute
> > method. For backwards compatibility you can check the list of
> > parameters and if the length is one and the first argument is a list,
> > tuple or dictionary change the arguments to the new style on the fly.
>
> -1
>
> As much as I'd like to be able to do this, I don't think this can be
> done in a backwards compatible way that is guaranteed to do the right
> thing in all cases. If the query has one placeholder and the parameter
> is a one-element sequence, it is impossible to know for certain whether
> the sequence itself or its only contained element should be bound as the
> parameter.

I agree that this is possible but it is a low enough occurrence that
it can be explicitly warned against -- backwards compatibility is not
perfect but it is reasonable considering that the DB API doesn't even
mention sequences (arrays) as possible parameter values; it only deals
with scalar parameter values.

> I think we should refuse the temptation to guess and go with the
> established semantics.

I suppose the other option is to come up with a new name for the new
syntax. Taking a page from some of the other modules that Python has,
perhaps

cursor.executev(statement, *args, *kwargs)

Maybe that is more palatable?

> --
> Carsten Haese
> http://informixdb.sourceforge.net
>
>
>