Re: the return of tables ()

On Tue, 2 Sep 2008 11:01:37 +0100, Tim Bunce <[email protected]>
wrote:

> > > I wasn't very clear (and was actually partly misleading). Sorry.
> > > 
> > > What I meant was that the TABLE_CAT and/or TABLE_SCHEM columns in the
> > > data returned by your table_info () method are probably empty strings but
> > > should be undefs.
> > > 
> > > What does
> > >     Data::Dumper::Dumper($dbh->table_info(...)->fetchall_arrayref)
> > > show for an example table?
> > 
> > $ perl -Iblib/{lib,arch} -MPROCURA::DBD -MData::Dumper
> > -wle'$dbh=DBDlogon;print Dumper $dbh->table_info(undef,"PROLEP","parm")->fetchall_arrayref' $VAR1 = [
> >           [
> >             '',
> >             'PROLEP',
> >             'parm',
> >             'T',
> >             'W'
> >           ]
> >         ];
> > 
> > Correct, as that is the result of
> > 
> > sub table_info
> > {
> 
> >     my $sth = $dbh->prepare (
> > 	"select '', OWNR, TABLE_NAME, TABLE_TYPE, RDWRITE ".
> > 	"from   SYS.ACCESSIBLE_TABLES ".
> > 	$where);
> 
> > select NULL, OWNR, ...
> > 
> > is not allowed. I don't see an easy way out
> > 
> > sql> select NULL, OWNR, TABLE_NAME
> > sql>    from SYS.ACCESSIBLE_TABLES
> > sql>    where TABLE_NAME like 'parm';
> > NULL is not allowed in a constant list (-10518).
> 
> Perhaps you could use some expression that happens to yield a NULL.
> Or you could implement a custom quote_identifier() method.

This worked:
--8<---
sub quote_identifier
{
    my ($dbh, @arg) = map { defined $_ && $_ ne "" ? $_ : undef } @_;
    return $dbh->SUPER::quote_identifier (@arg);
    } # quote_identifier
-->8---

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