Question

I am having a problem in writing the query for this. I have a q&a website where I want to find out the number of first answers by a user – for all the questions answered by a user, which answers were the first for the particular question.

I have two tables –

• questions – id, question
• answers – id, question_id, answering_userid, date

I have broken this into two steps

1. find out the answers by a user
   • SELECT id FROM answers WHERE answering_userid = “ABC”
2. find out if they are the first
   • ????? This is where I am having problem. I have figured that it will employ MIN(date).

Can somebody help me in implementing this?

Regards

Answer 1

With the help of another user codefly I have got the answer I was looking for.

select a.id, a.answering_userid
from answers a
inner join (
   select answering_userid, question_id, min(date) as mindate
   from answers
   group by question_id
) first on a.question_id = first.question_id 
    and a.date = first.mindate
    and a.answering_userid = first.answering_userid
where a.answering_userid = "ABC"