Re: the return of tables ()

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

> On Tue, Sep 02, 2008 at 12:39:41AM +0200, H.Merijn Brand wrote:
> > On Mon, 1 Sep 2008 22:59:24 +0100, Tim Bunce <[email protected]>
> > wrote:
> > 
> > > > > > > > As get_info (29) now returns a TRUE value, the 'tables ()' method is
> > > > > > > > using a different strategy to build the list it returns:
> > > > > > > > 
> > > > > > > >     sub tables
> > > > > > > >     {
> > > > > > > >         my ($dbh, @args) = @_;
> > > > > > > >         my $sth    = $dbh->table_info (@args[0..4]) or return;
> > > > > > > >         my $tables = $sth->fetchall_arrayref or return;
> > > > > > > >         my @tables;
> > > > > > > > »       if ($dbh->get_info (29)) { # SQL_IDENTIFIER_QUOTE_CHAR
> > > > > > > > »           @tables = map { $dbh->quote_identifier (@{$_}[0,1,2]) } @$tables;
> > > > > > > > »           }
> > > 
> > > > > > > > Unify has no support for CATALOG's, so the values in info are not
> > > > > > > > defined, but still used in the map, causing all my tables no showing up
> > > > > > > > with and empty "". in front of it, which is illegal to the database :(
> 
> > > I wasn't very clear (and was actually partly misleading). Sorry.
> > > 
> > > What I meant was that the TABLE_CAT and/or TABLE_SCHEM columns in the
> > > data returned by your table_info () method are probably empty strings but
> > > should be undefs.
> > > 
> > > What does
> > >     Data::Dumper::Dumper($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.

I tried, I cannot without creating a new table, and that feels like
shooting a mouse with an elefant;

> Or you could implement a custom quote_identifier () method.

I could, but that would feel very unsafe

-- 
H.Merijn Brand          Amsterdam Perl Mongers  http://amsterdam.pm.org/
using & porting perl 5.6.2, 5.8.x, 5.10.x, 5.11.x on HP-UX 10.20, 11.00,
11.11, 11.23, and 11.31, SuSE 10.1, 10.2, and 10.3, AIX 5.2, and Cygwin.
http://mirrors.develooper.com/hpux/           http://www.test-smoke.org/
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