On Mon, Apr 19, 2004 at 02:25:41PM -0700, Dean Arnold wrote:
> > On Mon, Apr 19, 2004 at 05:16:02PM +0200, Bart Lateur wrote:
> > > I'm working on a next generation of a DBI abstraction module...
> > >
> > > Sometimes it's necessary to specify the type of placeholder parameter,
> > > like
> > >
> > > use DBI ':sql_types';
> > > $dbh = DBI->connect(...);
> > > $sth = $dbh->prepare(...);
> > > $sth->bind_param(1, undef, SQL_INTEGER);
> > > $sth->bind_param(2, undef, SQL_VARCHAR);
> > > $sth->execute($param1, $param2);
> > >
> > > My question is, assuming I have fetched a
> > >
> > > $sth1 = $dbh->prepare(...);
> > > $sth1->execute();
> > >
> > > on the same table, before, is it safe to do:
> > >
> > > for my $i (0 .. $#fields) {
> > > $sth->bind_param($i+1, undef, $sth1->{TYPE}[$i]);
> > > }
> > >
> > > or are the values that the attribute TYPE holds, not compatible with this?
> >
> > Sadly not. The plan is for a ParamTypes attribute like ParamValues.
> > Patches welcome.
> >
> > Tim.
>
> Now I'm confused. Are we talking about the same processing here ?
Ah, no. I confused this with a different issue that came up a while ago.
> 1. The app wants to use the output of a prior execute()'s result
> set as the values for another $sth's parameter attributes. In that case,
> the example given should work (with the possible exception that
> PRECISION and SCALE need to be specified as well), eg,
> copying a table from one database to another.
I doubt any drivers have a bind_param() method that pays attention
to PRECISION and SCALE attributes. On the other hand, it should be
harmless to pass them.
More generally it's not clear that any given $sth->{TYPE} value for
output can be used as a TYPE value for bind_param(). It would certainly
be good if that were the case, but currently it's not mandated.
I'll make a note to consider this in relation to DBI v2.
> 2. The app wants $sth2 to "inherit" the placeholder attributes from
> $sth1's placeholders. I believe this is the issue Tim is addressing,
> and which is not currently supported....correct ?
Correct.
Tim.
