class ActiveRecord::DatabaseConfigurations

def find_db_config(env)

the first +DatabaseConfig+ for the environment.
If the application has multiple databases +find_db_config+ will return

Returns a single +DatabaseConfig+ object based on the requested environment. 
def find_db_config(env)
  env = env.to_s
  configurations.find do |db_config|
    db_config.for_current_env? && (db_config.env_name == env || db_config.name == env)
  end || configurations.find do |db_config|
    db_config.env_name == env
  end
end