Question

I have an Oracle query

select max(m.id),
       m.someId keep (DENSE_RANK FIRST ORDER BY m.UpdateDate desc) 
from MyTable m 
groupBy m.someId

which for data like this:

id UpdateDate someId
1  20-01-2012 10
2  20-01-2012 10
3  01-01-2012 10
4  10-02-2012 20
5  01-02-2012 20
6  01-04-2012 30

will return me exactly this:

2 10
4 20
6 30

So, for every someId it searches for latest updateDate and does return the appropriate id. (And if there are a several ids for the latest dates it takes latest id).

But for SQL server will this query work the same way? I mean this construction keep (dense_rank first order by ..)?

Answer 1

I don’t think that your particular query will run SQL Server. But you can achieve the same result doing this:

SELECT id, SomeId
FROM (  SELECT *, ROW_NUMBER() OVER(PARTITION BY someId ORDER BY UpdateDate DESC, id DESC) Corr
        FROM MyTable) A
WHERE Corr = 1