COMMIT after an ERROR?

Does an error during a transaction invalidate the transaction?

eg

  BEGIN
  SomeQueryThatSucceeds
  SomeQueryThatFails
  SomeOtherQueryThatSucceeds
  COMMIT

Will the transaction successfully COMMIT, or will the COMMIT fail?

Translation: Do I need to monitor for error conditions during a
transaction and manually do the ROLLBACK in those cases?

--
J C Lawrence
---------(*)                Satan, oscillate my metallic sonatas.
claw@kanga.nu               He lived as a devil, eh?
http://www.kanga.nu/~claw/  Evil is a name of a foeman, as I live.