# whenever you need to do a custom query/function/sproc into another DB that is not development
app = ActiveRecord::Base.establish_connection(
  adapter:  "mysql",
  host:     "localhost",
  username: "myuser",
  password: "mypass",
  database: "somedatabase"
)
# if you have already defined an entry in database.yml
# -------------- READ THIS TOO ---------------------------------
# use app = ActiveRecord::Base.establish_connection(:your_custom_db)

sql = <<-SQL
 select * FROM whatever_table( 'somestring', 2016 );
SQL
app.connection.execute(sql)