On Tue, 11 Dec 2001, Terrence Brannon wrote:
>
> On Monday, December 10, 2001, at 08:48 AM, Tim Bunce wrote:
> > At this point I'd just like to solicit some feedback from anyone
> > who's used DBIx::AnyDBD and got any ideas or comments etc about it
> > and how it could be improved.
> >
>
> I read over the docs and had a good night's sleep on this subject
> and now have the following points to make:
>
>
>
> 1 - In the examples directory, it bothers me that
> Example::DB::Default has 2 different types of things. On the one
> hand, it has generic SQL construction methods. On the other, it
> has a number of SQL operations for a particular app. I think the
> app-specific SQL belongs in Example::DB::Methods or something.
>
> And another thing, having a function for every SQL statement
> implies that they will all be in memory for the life of the
> application. I have worked at companies where we have 5000+
> queries. In this case, memory for all the strings becomes and
> issue. In this case, something like my module SQL::Catalog would
> have been useful, because all SQL strings are loaded and dropped
> from main memory for each query. I admit that this is time
> consuming, but one can't have the fastest system and the most
> memory efficient system.
>
> However, if something is going to be a part of DBI, shouldn't it
> be flexible enough to allow optimal query service in terms of
> either speed (in-memory functions as is done now) or memory
> (lexically scoped query strings which are destroyed on function
> exit)?
The example is just that - an example. You could layer SQL::Catalog on
top, in the default layer, for example, to get the feature you're after,
but still allow some DB specific procedures in the higher levels.
> 2 - I was a bit surprised that the subclasses in the examples
> hiearchy were so SQL oriented. I had expected to see "business
> operations" like "register_order", "load_customer_id", etc, etc.
>
> The SYNOPSIS does show one line which is a business operation:
>
> my @users = $db->get_users(); # called from Example/DB/Pg.pm
>
> but (a) it is not implemented and (b) it is not clear to me where
> in the object hierarchy business operations should be with
> respect to the AnyDBD classes. Ahh, this was answered
> above.Theyare in Default.pm and *textually* separated with the
> comment:
>
> ###############################################################
> # Main SQL methods here
> ###############################################################
>
> when in fact my feeling is they should be in their own class somewhere.
> 3 - I am on the Postgresql mailing lists and outer joins can be
> done in 7.1.3 using "OUTER JOIN ON" and not the (+) operator of
> Oracle. But your Pg.pm throws an exception:
>
> sub _outer_join
> {
> die "Cannot do outer joins in Postgres. This method needs to
> be hand coded\
> for Postgres.";
> }
Remember again, it's just an example! It's the general framework we should
be discussing, not the examples.
> which is no longer true for Postgresql. Which of course brings up
> the issues of creating subclasses not just on database type
> (oracle, mysql, etc) but also for various versions of the
> database (postgresql pre-7.1.3 versus 7.1.3 onward)
That's certainly something worth discussing. Same goes for MySQL with it's
different table types (InnoDB etc).
> 4 - DBIx::AnyDBD is nice for "runtime-SQL", that is SELECT,
> UPDATE, DELETE, INSERT, but it does not show support for
> "admin-SQL", in other words for table creation. My favorite
> module for this is Marcel Grunaer's DBIx::Renderer.
Right. It's meant to be a solution on which to build solutions, not the
end result. That's the point I think you've missed. AnyDBD is very simple
in what it does - it creates a class hierarchy. That's all. The rest is up
to you.
> 5 - Although I think I know the answer to this, it was not stated
> in direct terms enough for me. So, only the particular subclass
> (MyClass::Oracle or MyClass::Pg or MyClass::MySQL) is required
> dynamically right? Not all 3 are used by default right?
Right.
--
<!-- Matt -->
<:->Get a smart net</:->
