[Dbix-class] DBIx::Class, another data validation approach

[Moritz Onken]

Am 28.07.2009 um 10:59 schrieb Alexander Hartmaier:

> Am Dienstag, den 28.07.2009, 00:29 +0200 schrieb Rob Kinyon:
>> On Thu, Jul 23, 2009 at 08:28, Alexander
>> Hartmaier<alexander.hartmaier at t-systems.at> wrote:
>>> The DBMS validates data types, length, undef and foreign keys  
>>> anyway, so
>>> maybe using it as validator (parse its error messages) is a  
>>> possibility?
>>
>> The problem is that many DBMSes do -NOT- validate things sanely -
>> SQLite and MySQL being the biggest offenders, though every DBMS has
>> its problems. Oracle, for example, in 9.2.0.3 had an issue where
>> certain invalid datetime entries were accepted. Furthermore, part of
>> the benefit of an ORM is that it is DBMS-independent - I want to know
>> that the same value restrictions are going to be maintained  
>> regardless
>> of backend.
>>
>> And, finally, the biggest win for validation is things that DBMSes
>> cannot do. For example, a SMALLINT that, for business reasons, has to
>> be within 20 of another column. How do you express that constraint in
>> a DBMS-independent fashion?
>>
>> I, for one, cannot wait for our new Moose overlords!
>>
>> Rob
> I didn't mean that we don't need business logic or extended  
> validation,
> but use the basic validation the db does anyway instead of cloning it
> which could lead to different checks and a performance penalty (i  
> had to
> disable validation for an app that inserts lots of data because it
> wasn't fast enough).

I'm not sure whether the performance argument applies here because you
need a roundtrip to the database. This takes time, especially if the
database server is not located on the same machine as the app server.

moritz