How to use DBI module to retrive the primary key of any table

[Richard Jones]

I am trying to automate the use of several programs, so that I can build it one time and the when we plug in other 'methods' to the members the programming can still work without additional work needing to be done. My last problem is trying to recover the primary key on the fly of any given table.

I see primary_key_info in the DBI module documentation, but cannot get it to work...

I would appreciate any help you can be.

Thanks...

PS> here is what I'm trying to get to work:
my $sth = $dbh->primary_key_info(qq{SELECT FROM `tablenamehere`});
$sth->execute;
$_primaryKey = $dbh->selectrow_array();
$sth->finish();
$_primaryKey should now be the primary key, but it does not work.