Can I use String as ID type for mongodb document?

Question

I am using java/morphia to deal with mongodb. The default ObjectId is not very convenient to use from Java layer. I would like to make it a String type while keep the key genera

Answer 1

Yes, you can use a string as your _id.

I'd recommend it only if you have some value (in the document) that naturally is a good unique key. I used this design in one collection where there was a string geo-tag, of the form "xxxxyyyy"; this unique-per-document field was going to HAVE to be in the document and I had to build an index on it... so why not use it as a key? (This avoided one extra key-value pair, AND avoided a second index on the collection, since MondoDB naturally builds an index on "_id". Given the size of the collection, both of these added up to some serious space savings.)

However, from the tone of your question ("ObjectIDs are not very convenient"), if the only reason you want to use a string is you don't want to be bothered with figuring out how to neatly manage ObjectIDs... I'd suggest it is worth your time to get your head around them. I'm sure they are no trouble... once you've figured out your trouble with them.

Otherwise: what is your options? Will you concoct string IDs EVERY TIME you use a MongoDB in the future?