Config `db` cover host info

[mrxiaozhuox]

I'm using the URI to connect mongodb, but the URI is from env var, and I cannot change it, the default db is admin. so can I use db to cover the host info?

app.config["MONGODB_SETTINGS"] = {
    "db": "myapp",
    "host": "mongo://localhost:27017/admin",
}

I want this demo use myapp db, not admin.