Question

I have the following data:

id   date_modified   value
1    some_date       4
1    some_date       3
1    some_date       1
2    some_date       5
3    some_date       8
3    some_date       7
...

and this query gets the id and date_modified where date_modified is the latest date:

select bh.id, max(bh.date_modified) 
from my_table bh
group by bh.id;

which does this:

id   date_modified  
1    some_date       
2    some_date       
3    some_date       
...

where each date is the latest date for each id which is nearly what I want.

How do I change the group by to get the value out? It’s the value that I’m interested in but I need to group using the id.

Many thanks.

Answer 1

Try this:

SELECT id, date_modified, value
FROM
(
    SELECT
        id, date_modified, value, ROW_NUMBER() OVER (PARTITIOn BY Id ORDER BY date_modified DESC) RN
    FROM tbl
) A
WHERE RN = 1