REST API (Mongo DB) Arguments Error 500 - node.js

Question

I have a Problem in with my REST API. It will not correctly communicate with mongodb. Node.js throw following Exception:
Error: Argument passed in must be a single String of 12 bytes or a string of 24 hex characters
My Manager looks like follows:
app.get('/users/:id', function(req, res) {
userProvider.fetchUserById(req.params.id, function(error, user) {
if (user == null) {
res.send(error, 404);
} else {
res.send(user);
}
});
});
My Provider looks like follows:
this.fetchUserById = function(id, cb) {
this.db.collection(usersTable, function(error, users) {
if (error) {
cb(error, null);
} else {
users.findOne({
_id:users.db.bson_serializer.ObjectID.createFromHexString(id)
}, function(error, result) {
cb(error, result);
});
}
});
};
My Mongoobject looks like follows:
{
"title": "title",
"givenname": "Vorname",
"lastname": "Nachname",
"name": "Vorname Nachname",
"username": "Benutzername",
"password": "Kennwort",
"email": "kuerzel#emailadresse.de",
"phone": "0000 - 000000",
"fax": "000000 - 000000",
"lastlogin": "15.11.2013",
"createdate": "15.11.2013",
"changedate": "15.11.2013",
"state": "1",
"_id": ObjectId("5283fbf56e3adb01f1000001")
}
When I now send a GET: /users/1 the error will thrown.
I´am new in Node.js. :-)

Answer 1

If your human readable IDs are unique, you can use them.
Just insert the documents with your nice id:
db.users.insert({ _id: myVeryNiceUniqueId, title: '...' }, ...);
As alternative, you could add an additional 'external id' to the document and create an unique index. But you will get many, many problems when you want to scale (sharding). Who is going to create the unique IDs? You will have something not-so-human-readable, I promise.
Edit
In Mysql I have start the Ids from 5XXXX and used them. How can I realize this with mongodb
You should ask another question or search answers. It is not a trivial task and you have to take concurrency into account. Maybe the concept of findAndModify or "Upsert" could help you. One of the most important things is that you need a way of atomic updates for the ID-generator. In one project in past I used Redis for this, but I'd always use MongoDB IDs since then. You should know that MongoDB ObjectIDs usually are generated by the Client-Driver. For REST services this is ideal: save document to DB and return status 201 Created, url=.../user/98357348957.
btw. should I generate the OrderIDs in Javascript by checking the highest value of an external id in the collection?
As said, you can get into trouble with usage of duplicate IDs when your server is in high contention. Try to find a solution with findAndModify or cache a block of IDs and use them in one process. I probably wouldn't search max and increment but use a special collection for ID-management.
What is here best practice?
Don't know. Using an ID-Generator. Depends on your enviroment (single process, single machine). If it is a simple setup, you'll find simple solutions. The setup for Twitter is not simple and they have developed a solution called twitter / snowflake. If you really want very nice, short IDs, but you have more than one process/machine, Redis might be want you want. And if the ID doesn't have to be contigous (without small gaps), you could draw a bunch of new IDs (e.g 100) and cache them for future consumption per process.
Can I hash the objectID to an 5 digit number?
No, there is no guarantee that this number is unique.