从条目组中选择一个不同的行

Question

ID  TYPE     DATE
1    A    01/02/2019
1    B    01/21/2019
1    C    02/03/2019
2    A    01/04/2019
2    C    01/29/2019
3    A    01/14/2019
3    B    03/11/2019

So using the table above as an example what I'm trying to do with a similar table is extract a specific Type from each Distinct ID. So let's say I only want to Select Type B from each Distinct ID. Now, the big confusion starts for me when I incorporate the Date. I want to Select Type B from each ID but only if Type B is the most recent date.

So in this instance the only row with Type B as the last date would be the last row.
3 B 03/11/2019

Any suggestions as to what my query should look like?

Answer 1

With NOT EXISTS:

select t.* from tablename t
where t.type = 'B'
and not exists (
  select 1 from tablename
  where id = t.id and date > t.date
)

See the demo .
Results:

| ID  | TYPE | DATE                |
| --- | ---- | ------------------- |
| 3   | B    | 2019-03-11 00:00:00 |