How to handle DB passwords in R connection strings?

Though I don't know what the SO quorum would be, the question itself is simple: How do y'all handle passwords in db connection string when you connect to a database from R?

Tutorials often show an example like this.

con <- dbConnect(MySQL(), user="root", password="test", 
             dbname="research_db", host="localhost",
             client.flag=CLIENT_MULTI_STATEMENTS)

If the database is indeed your experimental localhost, this might be somewhat realistic. However if you use it with multiple users on a server you might not want to expose the db credentials like this. Particularly when combining RStudio Server with a SQL database you might want to do something encrypted. What is your experience?