Windows Function

Question

Hi All,
I have the following query to get the latest record.
SELECT DISTINCT t1.amendment_id, t2.amend_status_code,
                RANK () OVER (PARTITION BY t1.amendment_id ORDER BY t2.entry_date DESC)
                                                                         RANK,
                t2.entry_date
           FROM amendment t1, amendment_status_history t2
          WHERE t1.amendment_id = t2.amendment_id
       GROUP BY t1.amendment_id, t2.amend_status_code, t2.entry_dateBut when i add in a condition after the WHERE statement " AND RANK () OVER (PARTITION BY t1.amendment_id ORDER BY t2.entry_date DESC)=1" I'm getting the "windows function is not allowed here" message. How can i solve this ? how can i get the records where the rank field has a value of '1'?
Thanks

Answer 1

Somethink like this
select * from (SELECT DISTINCT t1.amendment_id, t2.amend_status_code,
                RANK () OVER (PARTITION BY t1.amendment_id ORDER BY t2.entry_date DESC)
                                                                         RANK,
                t2.entry_date
           FROM amendment t1, amendment_status_history t2
          WHERE t1.amendment_id = t2.amendment_id
       GROUP BY t1.amendment_id, t2.amend_status_code, t2.entry_date) where rank = 1