[Dbix-class] [OT][ANNOUNCE] SQL Generation with SQL::DB

[Mark Lawrence]

On Fri Sep 07, 2007 at 11:07:26AM +0200, Emanuele Zeppieri wrote:

> >    ($track->length > 248) & ! ($cd->year < 1997)
> 
> No, I'm asking how it could be *built* by code without string 
> concatenations/interpolations.

Don't forget, the operators in the above statements are not strings,
so concatenation won't work anyway.

> (For example, think of arbitrarily data input by the user via a search 
> form that the code has to turn into (arbitrarily complex) where clauses).

    my $length = $form->param('length');
    my $year   = $form->param('year');
    my $not    = $form->param('not');

    my $expr = SQL::DB::Expr;

    if ($length) {
        $expr = $track->length > $length;
    }

    if ($year) {
        if ($not) {
            $expr = $expr & ! ($cd->year < $year);
        }
        else {
            $expr = $expr & ($cd->year < $year);
        }
    }


Cheers,
Mark.
-- 
Mark Lawrence