my %IMG_FIELDS = { field1 => 'Field1', field2 => 'Field2', }; die "Invalid img parameter $img" unless $IMG_FIELDS{$img}; my $sql = "SELECT $IMG_FIELDS{$img} FROM listings WHERE pc_mls_id = ?"; my $sth = $dbh->prepare($sql) or die "Couldn't prepare: $DBI::errstr\n"; $sth->execute($mls_id);