R

The examples below show how to retrieve the password from an environment variable and use it to connect.

# dplyr lets you program the same way with local data frames and remote SQL databases. 
install.packages("dplyr") 
library("dplyr") 
db <- src_postgres(dbname="test_db", host="localhost", port=5432, user="cdswuser", password=Sys.getenv("POSTGRESQL_PASSWORD")) 
flights_table <- tbl(db, "flights") 
select(flights_table, year:day, dep_delay, arr_delay)