How to get the Mongo database specified in connection string in C#

Update:

MongoServer.Create is obsolete now (thanks to @aknuds1). Instead this use following code:

var _server = new MongoClient(connectionString).GetServer();

It's easy. You should first take database name from connection string and then get database by name. Complete example:

var connectionString = "mongodb://localhost:27020/mydb";

//take database name from connection string
var _databaseName = MongoUrl.Create(connectionString).DatabaseName;
var _server = MongoServer.Create(connectionString);

//and then get database by database name:
_server.GetDatabase(_databaseName);

Important: If your database and auth database are different, you can add a authSource= query parameter to specify a different auth database. (thank you to @chrisdrobison)

From docs:

NOTE If you are using the database segment as the initial database to use, but the username and password specified are defined in a different database, you can use the authSource option to specify the database in which the credential is defined. For example, mongodb://user:pass@hostname/db1?authSource=userDb would authenticate the credential against the userDb database instead of db1.

In this moment with the last version of the C# driver (2.3.0) the only way I found to get the database name specified in connection string is this:

var connectionString = @"mongodb://usr:[email protected],srv2.acme.net,srv3.acme.net/dbName?replicaSet=rset";
var mongoUrl = new MongoUrl(connectionString);
var dbname = mongoUrl.DatabaseName;
var db = new MongoClient(mongoUrl).GetDatabase(dbname);
db.GetCollection<MyType>("myCollectionName");