SQL: How to order values inside group by
- by Denis Yaremov
Consider the following MS SQL Server table:
  ID  |   X   |   Y
------+-------+-------
   1  |   1   |   1
   2  |   1   |   2
   3  |   1   |   3
   4  |   2   |   40
   5  |   2   |   500
   6  |   3   |   1
   7  |   3   |   100
   8  |   3   |   10
I need to select the ID of the row that has the maximum value of Y grouped by x, i.e:
  ID  |   X   |   Y
------+-------+-------
   3  |   1   |   3
   5  |   2   |  500
   7  |   3   |  100
The query will be nested several times so an optimal performance solution is required...
Thank you!