#open connection to the database
my $db = DBI->connect("dbi:Oracle:host=$host;sid=$sid;port=$port", $uid, $pwd) or die "Error while connecting to database!!!\nIncorrect Connection information\n";
 
my $SQL_query;
    
    $SQL_query = qq {SELECT A.DISPLAY_ORDER, A.NAME PARENT_NAME, B.NAME CHILD_NAME FROM CATEGORY A, CATEGORY B WHERE B.ID_PARENT_CATEGORY(+) = A.ID_CATEGORY AND A.DISPLAY_ORDER != -1 ORDER BY DISPLAY_ORDER};
                            
    debug($SQL_query);
    
    my $sth = $db->prepare( $SQL_query )  or die "Can't prepare SQL statement: $DBI::errstr\n";
    
 ### Execute the statement in the database
 $sth->execute or die "Can't execute SQL statement: $DBI::errstr\n";
 
my ($pdisplay_order, $parent_name, $child_name);
   
 # Bind perl variables to columns:  
 my $rv = $sth->bind_columns(\$pdisplay_order, \$parent_name, \$child_name);
 
### Retrieve the returned rows of data
 while ($sth->fetchrow_array()) {
 chomp($pdisplay_order);
 chomp($parent_name);
 chomp($child_name);
 
 print "$pdisplay_order, $parent_name, $child_name\n";
 }