Question

I’m new to SQL and am trying to learn it. A problem that occurred to me was how to find the maximum number of specific occurrences for a person in a table. I’m not sure how the query would compare each ID with another ID and keep track of the count. Poor explanation, but here is a dataset that will hopefully make it more clear.

players:
+--------+--------+
| pid    | name   |
+--------+--------+
| 1      | Tom    |
| 2      | Sam    |
| 3      | Dan    |
+--------+--------+

scores:
+--------+--------+--------+
| sid    | pid    | result |
+--------+--------+--------+
| 1      | 1      | miss   |
| 2      | 1      | hit    |
| 3      | 3      | hit    |
| 4      | 2      | miss   |
| 5      | 3      | hit    |
| 6      | 3      | hit    |
+--------+--------+--------+

The expected answer would be pid = 3, name = Dan because he had the most hits out of all the other players.

Answer 1

Select
  p.pid,
  p.name
From (
  Select
    p.pid,
    p.name,
    count(*)
  From
    players p
      inner join
    scores s On
      p.pid = s.pid
  Where
    result = 'hit'
  Group By
    p.pid,
    p.name
  Order By
    count(*) Desc
  ) p
Where 
  rownum = 1;

http://sqlfiddle.com/#!4/03ba0/22