要看原句的时态.如果像你说的这句,i had a good time,则改为did you have a good time?
如果是she/he had a good time,则改为did she/he have a good time?
如果是she/he has a good time,则改为does she/he have a good time?
如一楼兄弟所说,做题是可以这么做,正常情况下一般还是问how are you doing比较多.意思为“最近过的如何”,在国外比how are you用的多.不过很少会出现how were you doing这种情况.