This query: "
UPDATE table_name SET column_name=$inputUpdate[0] WHERE column_name=$input[1]" can update more than one rows at once! Probably it is not what you want. There some unique index column must be used for update.
I suggest to have two hashes: %input, and %inputUpdate instead of arrays. Those hashes contain ColumnName => value pairs.
Than, assuming ID is identity column:
my %update =
map {$_ => $inputUpdate{$_} }
grep {$inputUpdate{$_} ne $input{$_} }
keys %input;
$dbh->do(<<"SQL", undef, values %update, $input{ID});
update TableName
set @{[ join ', ', map {"$_ = '?'"} keys %update]}
where ID = ?
SQL
$dbh->commit;
