Unique roundquestion
The answer to a roundquestion should be unique. A user should not be able to answer the same roundquestion twice. (Though, he may very well be able to answer the same question twice.
IMPORTANT
After merging this request, the database has to be updated.
ALTER IGNORE TABLE useranswer ADD CONSTRAINT UNIQUE (name, roundquestion);
IGNORE
results in the removal of duplicates with random preference.
It may be preferable to manually resolve duplicates first.