How to name mongodb collections as email names

Question

I want to name mongo collections after email addresses, how can I do this? is there a way to escape . and @ ?

Answer 1

There is nothing wrong with naming a collection like this. There is a section within the documentation on collection names under the general title of limitations:

Basically these:

In version 2.2, collection names cannot:

• contain the $.
• be an empty string (i.e. "").

So you seem to be missing the real operators other than the "shorthand" variable notations available under the mongoDb shell:

 db.createCollection("this@my.com")
 db.getCollection("this@my.com").insert({ a: 1 })
 db.getCollection("this@my.com").find()

All of those methods are available to drivers as well.

Not sure what the utility of this is, it would seem better to just use the "email" as a key within your documents than create separate collections for these.

Answer 2

You can use the following command

db.runCommand({"create":"a@b.com"});

This will create the collection with @ in its name, you'll get following output indicating collection creation.

{ "ok" : 1 }

Answer 3

As others have mentioned '@' is valid, it is not noted in the collection name restrictions.

Some other considerations that you might want to make however:

• The maximum length of a MongoDB collection is 120 bytes (I think it ends up being 116 characters). The maximum length of an email address is 254 characters.

• There is a limit on the maximum number of collections in MongoDB which is based on the size of your namespace file. Using defaults you are essentially limited to 24,000 collections + indexes. See MongoDB Limits and Thesholds and also this question [limits of number of collections in databases. Given this limit, even if you were to raise it to the maximum using a larger namespace file, you should consider if it's possible that you might exceed this limit in your particular application

• Querying across collections is not easy, so make sure that you don't have any use cases that might require this

Assuming that you may be building some sort of multi-tenant application, there are a number of resources out there that weigh the various options. Check out Building Multi-tenant applications on MongoDB.