[DB-SIG] ctsybasemodule problem and dbi question

[Greg Stein]

Cameron Mellor wrote:
> 
> From: M.-A. Lemburg <mal@lemburg.com>
> >...
> >I think dbi is not really needed anymore: The only two types I can
> >think of where it has some use are date/time values (use mxDateTime
> >for those) and RAW input values (don't know how important it is
> >to be able to differentiate between plain strings and RAW input --
> >plain Python strings work just fine for mxODBC in both modes).
> 
> I thought they were there as placeholders: that is, you knew from the data
> that it was "special" and needed appropriate handling. Anyway, I'll take a
> closer look and see what I can find. I may end up using ctsybase anyway
> (since I'm playing with Sybase at the moment) and I don't really want it
> dumping core. :-/

The dbiRAW type is mostly for *input* binding rather than output. As I
recall, the Oracle database requires you to bind LONG / LONG RAW columns
differently than VARCHAR columns. The dbiRAW type allows the execute()
method to use the appropriate binding mechanism -- based on the argument
being a string or a dbiRAW object.

Note: at the time the Oracle code was written, there was no way for the
execute() method to figure out the right way to bind the input. Maybe
Oracle has provided a way to prepare an INSERT statement, check the
implied input types, and then perform the bind. Somehow, I doubt it
though.

The dbiDATE type exists for a similar reason: there was no way for the
DB modules to determine that a particular input was a date. Presuming
that a standard type is established for time/date handling (such as
mxDateTime), then the DB module can do the input binding properly.

A similar situation would arise for money types or other special column
types. If the underlying database requires that a column must be bound
in a special way for that type, then the DB module must figure that out
from the type of the arguments (since it has nowhere else to turn to for
the info).

Marc: did I see somewhere that Guido might incorporate mxDateTime as a
standard module in 1.6 or something like that?

Cheers,
-g

--
Greg Stein, http://www.lyra.org/