I have a table that store ticket and statue relation
x
ticketstatus_Id ticket_Id status_Id
===================================
1 1 1
2 1 2
3 1 3
4 2 1
5 2 2 *
6 3 1
7 4 1
8 3 2 *
I want to select rows that last status_Id equal 2 ,Rows are marked in table. I think I have to use GROUP BY on column ticket_Id but it return with first status_Id.
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Answer
This problem is a good candidate for ROW_NUMBER
:
WITH cte AS (
SELECT *, ROW_NUMBER() OVER (PARTITION BY ticket_Id ORDER BY ticketstatus_Id DESC) rn
FROM yourTable
)
SELECT ticketstatus_Id, ticket_Id, status_Id
FROM cte
WHERE rn = 1 AND status_Id = 2;
The above logic finds all latest rows for each ticket_Id
, as ordered by the ticketstatus_Id
, whose status_Id
values also happens to be 2.