establish_connection does not raise exception for wrong password


When changing the default yaml-defined-connection via the
establish_connection in,
say, a login controller (we are using user-level access to our
database), wrong
credentials are not immediately notified (no exception is raised).
Instead, this
happens only at the first database access after the
establish_connection call:

  ActiveRecord::Base.establish_connection(...<wrong pwd>)
    ... # not getting here

  ActiveRecord::Base.establish_connection(...<wrong pwd>)
    ... # getting here, $! containing (Oracle) database error message,
saying pwd is wrong

Is this a bug, or a feature?

Thanks for any hints,

   raise NameError, "something went wrong"
rescue => e
   puts "Caught: #{}"

rescue => e
is exactly equivalent to:
rescue StandardError => e

If you need to catch more than StandardError, you can use:
rescue Exception => e

Or catch some other branch of the Exception hierarchy
rescue ScriptError => e # subclass of Exception
rescue LoadError => e # subclass of ScriptError

Or even less than StandardError
rescue IOError => e # subclass of StandardError
rescue EOFError => e # subclass of IOError

And, of course, 'e' is just a local variable so use your favorite name if 'e' doesn't feel right (but it is a very common idiom).


Rob Biedenharn