not-null property references a null or transient value

org.springframework.dao.DataIntegrityViolationException: not-null property references a null or transient value : entity.VoiceProfile.email; nested exception is org.hibernate.PropertyValueException: not-null property references a null or transient value : entity.voiceProfile.email

 conclustion :
 While persisting into the DB get the users VoicePofile by id or check if any user exist for the voiceprofile or not.
 if exist get and then store in db.