UPDATE table SET business = ? ..
       ^^^^^ this should be the table name users
##</code><code>##

or die "Error Preparing:\n" . $stmt . "\nDBI returned: \n", $dbh->errstr;
..
or die "Unable to execute query: " . $sth->errstr;

##</code><code>##

sub update_insert_Record {

  warn("522 update_insert_Record");
  my $post = $query->param("post");
  return if ($post);
  
  my $user_id = $query->param('user_id');

  my @form = qw(id username password pin position forename
                lastname business address1 address2 city state zip
                email phone_home phone_cell comments MJ MD DD DP);
    
  # UPDATE existing record
  my %newData = map{ $_ => $query->param{$_} } @form;  
	
  #Recover existing values from database and fill variables
  my $stmt = 'SELECT * FROM users 
              WHERE user_id = ?';

  warn("statement =  '$stmt'");	

  my $sth = $dbh->prepare($stmt);
  $sth->execute($user_id);	
  my $oldData = $sth->fetchrow_hashref();   

  my @fields;
  my @values;
  # compare old v new
  for (sort keys %newData){
    if ($newData{$_} ne $oldData->{$_}){
      push @fields,"$_ = ?";
      push @values,$newData{$_};
    }
  }

  # skip if no change
  if (@fields == 0){
    print "No update required\n";
  } else {
    # build sql
    my $fields = join ',',@fields;
    my $stmt = "UPDATE users SET $fields WHERE user_id = ?";
    #add id
    push @values,$user_id;
 
    warn("statement =  '$stmt'");	
 
    # prepare and execute sql
    # print "$stmt\n(@values)\n"; 		
    $sth = $dbh->prepare($stmt);
    $sth->execute(@values);
  }
}