Survey Answer table[survey_mrq_answers] need to be optimised [ avoid duplicate ]

[subakarank]

I have two survey questions under one section. Firs time I have submitted answer for one question. Answer's table saved my input. Second time I submit answer for second question .This time system has re-recorded my answer for first question[no override]. Eventually I answered for two question but system saved three records. First question's answer two time(one with deleted at fields and one more as new) and second question's answer one time .

Need to fix : must be overridden whenever we do survey.