MongoDB PHP UTF-8 problems

Question

Assume that I need to insert the following document:

{
    title: 'Péter'
}

(note the é)

It gives me an error when I use the following PHP-code ... :

$db->collection->insert(array("title" => "Péter"));

... because it needs to be utf-8.

So I should use this line of code:

$db->collection->insert(array("title" => utf8_encode("Péter")));

Now, when I request the document, I still have to decode it ... :

$document = $db->collection->findOne(array("_id" => new MongoId("__someID__")));
$title = utf8_decode($document['title']);

Is there some way to automate this process? Can I change the character-encoding of MongoDB (I'm migrating a MySQL-database that's using cp1252 West Europe (latin1)?

I already considered changing the Content-Type-header, problem is that all static strings (hardcoded) aren't utf8...

Thanks in advance! Tim

Answer 1

JSON and BSON can only encode / decode valid UTF-8 strings, if your data (included input) is not UTF-8 you need to convert it before passing it to any JSON dependent system, like this:

$string = iconv('UTF-8', 'UTF-8//IGNORE', $string); // or
$string = iconv('UTF-8', 'UTF-8//TRANSLIT', $string); // or even
$string = iconv('UTF-8', 'UTF-8//TRANSLIT//IGNORE', $string); // not sure how this behaves

Personally I prefer the first option, see the iconv() manual page. Other alternatives include:

• mb_convert_encoding()
• utf8_encode(utf8_decode($string))

You should always make sure your strings are UTF-8 encoded, even the user-submitted ones, however since you mentioned that you're migrating from MySQL to MongoDB, have you tried exporting your current database to CSV and using the import scripts that come with Mongo? They should handle this...

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EDIT: I mentioned that BSON can only handle UTF-8, but I'm not sure if this is exactly true, I have a vague idea that BSON uses UTF-16 or UTF-32 to encode / decode data, but I can't check now.