Question

Suppose I have a table with some natural grouping and ordering, for example records by date, where the records for any given date are ordered by some other differentiator field

   1 July, 1, 56.6
   1 July, 2, 45.8
   1 July, 3, 78.9
   2 July, 1, 34.2
   2 July, 2, 26.7

I want to select the records with the highest differentiator for each day, for example, to get at

   1 July, 3, 78.9
   2 July, 2, 26.7

in this simple case. I can’t think how to structure a query to retrieve those records. So far I’m pulling back the whole set and selecting in Java – not really what i want to do.

Answer 1

Perhaps something like,

Select o from MyClass o where o.value = (Select Max(g.value) from MyClass g where g.date = o.date)