PurposeDiscards any changes that have been made during an update.
def b = Book.get(1) b.title = "Blah" b.discard() // changes won't be applied now
discardmethod informs the persistence context that an instance should not be saved. The
discardmethod is equivalent to using Hibernate's evict method.
Note that this method will not clean or reset the object with the original values it will just prevent it from being automatically saved by Grails.