MongoDB IRepository db Connections

This is what I have so far with regards to my IRepository for MongoDB and was wondering whether or not I'm on the right lines?

public abstract class Repository<TEntity> : IRepository<TEntity> {

    private const string _connection = "mongodb://localhost:27017/?safe=true";
    private MongoDatabase _db;
    protected abstract string _collection{get;}

    public Repository() {
        this._db = MongoServer.Create(_connection).GetDatabase("Photos");
    }

    public IQueryable<TEntity> FindAll() {

        return this._db.GetCollection<TEntity>(_collection).FindAll().AsQueryable();
    }
}

This way I can create my PhotoRep开发者_C百科ository class that inherits from here and supplies the required _collection name.

I just want to make sure that I'm opening the connection to the db in the correct place and in the correct way.

Yes, this is fine. MongoServer.Create will return the same instance of MongoServer when passed the same connection string, so it is safe to call MongoServer.Create as many times as you want.