[Dbix-class] Auto-joins

[Matt S Trout]

Nilson Santos Figueiredo Junior wrote:
> On 3/30/06, Matt S Trout <dbix-class at trout.me.uk> wrote:
>> quick example for you from the S::A tests
>>
>> [-maybe => {race => [-and => [qw(black white asian)]]},
>>    {-nest => {firsttime => [-or => {'=','yes'}, undef]}},
>>    [ -and => {firstname => {-not_like => 'candace'}},
>>              {lastname => {-in => [qw(jugs canyon towers)]}} ] ] ]
>>
>> making it work for trivial queries is trivial. making it work for every
>> possible query is more complex :)
> 
> Yes. But I think it's better to be able to auto-join simple queries
> than to not do it at all.

Don't like that approach. In my experience magic that doesn't work entirely 
tends to be a bad design decision in the long run, since it often fails in odd 
ways. Class::DBI's magic drove me insane when it didn't quite work, because I 
usually had to bypass it entirely. Which has often far too hard.

> Actually, I'd never write queries like this example.
> Anything that gets a little more complex will, usually, be much more
> readable as plain SQL. I mean, the end of this query looks like Lisp
> on steroids (i.e. with brackets and curly braces besides parens). It's
> damn ugly.

I like lisp :)

> I know this might be seen with some criticism, but I'd rather maintain
> SQL statements than that complex data structures mess and I know this
> query is actually not that complex.

That's great until you need to add an extra chunk to the query 
programmatically, at which point stuff gets hard.

> Anyway... why not patching SQL::Abstract? Or is it somehow unpatchable
> (i.e. so badly messed up that you wouldn't touch it with a 10 foot
> pole)?

It would need the best part of a rewrite; the _recurse_where method is kinda 
monolithic. Plus I haven't been able to raise the author by e-mail.

-- 
      Matt S Trout       Offering custom development, consultancy and support
   Technical Director    contracts for Catalyst, DBIx::Class and BAST. Contact
Shadowcat Systems Ltd.  mst (at) shadowcatsystems.co.uk for more information

+ Help us build a better perl ORM: http://dbix-class.shadowcatsystems.co.uk/ +