Question

I am learning SQL and do some practice on the internet.

I cannot find the answer for the problem 4a and 4b on http://sqlzoo.net/2b.htm
The table’s name is nobel and have 3 colums (yr, subject, winner)

The question is:

Show the years in which three prizes were given for Physics.

Show winners who have won more than once.

Thanks

Answer 1

This should do it for 4a:

SELECT yr
  FROM nobel
 WHERE subject = 'Physics'
 GROUP BY yr
HAVING COUNT(*) = 3;

And for 4b:

SELECT winner
  FROM nobel
 GROUP BY winner
HAVING COUNT(*) > 1;