Postgresql extract last row for each group

I have the following data

For each group app and user, I need to get the latest login date. I tried to use a window function, but could not get the result of what I am expecting:

SELECT app, people, LAST_VALUE(login) OVER (PARTITION BY app, people ORDER BY login)
FROM xxxxx

Any suggestions?

>Solution :

You can use the MAX window function in place of the LAST_VALUE window function:

SELECT app, 
       people, 
       MAX(login) OVER (PARTITION BY app, people ORDER BY login DESC)
FROM tab

Check the demo here.

Instead, if you want to aggregate your "app" and "people" values on the last login value, you can also use the MAX aggregation function:

SELECT app, 
       people, 
       MAX(login)
FROM tab
GROUP BY app, 
         people

Check the demo here.