pdo design

Hey Ard,

When you say database, do you mean separate database connection, or separate
named databases on the same connection?

PDO::beginTransaction() initiates a transaction for a given connection ($dbh)
in a more or less portable way. You're not always guaranteed to be able to do
that; extending it for multiple database handles seems a bit optimistic :)

Could you expand on what Firebird does here? Are there other DB's that
support this too?

--Wez.

-----Original Message-----
From: Ard Biesheuvel [mailto:a.k.biesheuvel@ewi.tudelft.nl]
Sent: 22 May 2004 16:39
To: internals@lists.php.net
Cc: helly@php.net; ilia@prohost.org; wez@thebrainroom.net;
george@omniti.com
Subject: pdo design

Guys,

I saw the alpha of PDO on pecl. I was wondering if we could
discuss the
design of it a bit more before putting too much work into it.

In particular, the way transactions are represented is not very
practical. Generally, databases that support transactions
will support
multiple concurrent transactions against the same database. Firebird
also supports transactions against multiple databases. [which
does not
mean you can join tables from different DBs, it just means ACID over
multiple DBs]

This means that in some cases you must specify both the
connection and
the transaction when generating a statement. [I'm not sure if others
RDBMSs support this, but it might be something we will see
more in the
future.]

In short:

In addition to $db->startTransaction(), maybe we could add
PDO::startTransaction($db1 [,$db2 [,$db3]]).

In addition to $db->prepare(), maybe we could add a Transaction
interface whose instances would allow being called as

$trans->prepare($query)

and maybe even

$trans->prepare($db, $query)

Your thoughts please ?

--
Ard