Final order, defined; appeal.

(1) The following are final orders which may be vacated, modified, or reversed: (a) An order affecting a substantial right in an action, when such order in effect determines the action and prevents a judgment; (b) An order affecting a substantial right made during a special proceeding; (c) An order affecting a substantial right made on summary application in an action after a judgment is entered; and (d) An order denying a motion for summary judgment when such motion is based on the assertion of sovereign immunity or the immunity of a government official. (2) An order under subdivision (1)(d) of this section may be appealed pursuant to section 25-1912 within thirty days after the entry of such order or within thirty days after the entry of judgment.