Re: CDBI and Sybase quirks

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> Trouble is that Class::DBI wants to write to primary key
> fields, so we need to prohibit that. Easily done:
>
> MSDW::MDP::Db::Release->flag_column(IDENTITY => qw/release_id/);

Interesting. Why don't you just use a column group though?

> sub _auto_increment_value {
>   my $self = shift;
>   my $dbh  = $self->db_Main;
>   my @primary_columns = $self->primary_columns;
>
>   #The sybase way
>   my $id;
>   eval {
>     #Can't use placeholders (not conditions)
>     my $sth = $dbh->prepare("select MAX( $primary_columns[0] ) from " .
>                             $self->table);
>     $sth->execute();
>     $id = ($sth->fetchrow_array)[0];
>   };
>   $self->_croak("Can't get last insert id") unless defined $id;
>   return $id;
> }

This will fail when AutoCommit is on. It's also not a very Sybase-like
implementation; "select @@identity" is the Sybase way. Anyway, I would
probably try to use the DBI's last_insert_id() method if possible. The
DBD::Sybase implementation of last_insert_id() has some caveats though, so
read the following documentation:

http://search.cpan.org/~mewp/DBD-Sybase-1.04/Sybase.pm#Behavior_of_$dbh-%3Elast_insert_id

> So this now works. Next issue is text fields. They cannot be used in
> placeholders ('?') with DBD::Sybase. So we override _insert_row and
> update :

I've encountered this problem with text fields and placeholders myself.
Fortunately for me, I was able to change the text fields to large varchar()
fields, but that's not feasible in a lot of cases, I'm sure.

Again, I would just use a column group to specify the text fields, instead of
this flag_column() method, but, otherwise, this looks rather useful and
something like it should be considered for inclusion in Class::DBI::Sybase, I
think. Have you contacted the author of Class::DBI::Sybase?

Best wishes,
Ed