# PDO questions

- Thread: https://externals.io/message/15174
- Original archive: https://news-web.php.net/php.internals/15174
- Started by Ard Biesheuvel on 2005-02-24T10:47:24+00:00
- Messages: 3
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## #15174 — Ard Biesheuvel — 2005-02-24T10:47:24+00:00

URL: https://externals.io/message/15174#15174

Some questions that came to mind while working on PDO/Firebird:

- why can't stmt_get_col() return a zval directly?
- why is there no PDO_PARAM_DOUBLE?

-- 
Ard

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## #15176 — Alan Knowles — 2005-02-24T12:20:55+00:00

URL: https://externals.io/message/15174#15176 · In reply to: #15174

At present it is nearly possible to write extensions that bypass the PDO
php api, and talk directly to the drivers via the PDO Api

- it helps alot that the backends where designed not to return zval's
much (meta is a rather messy exception, that hopefully may get looked at
after 5.1 I guess). 

I think Wez, pretty correctly doesnt want to go too far with datatype
abstraction in PDO, I've got some way with making DBDO use PDO as a
backend, and it has a far more comprehensive datatype abstraction. (as
that is one of it's primary focuses.)
But the fact that meta is returning zval's is a bit of a pain, that I've
been putting off dealing with it this week.

Regards
alan


> stmt_get_col
.. .stupid evolution deleted stuff ....

-- 
Alan Knowles <alan@akbkhome.com

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## #15182 — Wez Furlong — 2005-02-24T15:20:53+00:00

URL: https://externals.io/message/15174#15182 · In reply to: #15174

> Some questions that came to mind while working on PDO/Firebird:
> 
> - why can't stmt_get_col() return a zval directly?
> - why is there no PDO_PARAM_DOUBLE?

Because PDO doesn't believe in doubles.  The decimal data coming back
from most databases is precise decimal data; converting it to double
instantly loses precision.

The idea of get_col() is that you pass back the native C-style type,
and leave it to PDO to manage the creation of a zval, where
appropriate.  The simplifies the common cases in developing database
drivers.

--Wez.