SQL Select where LINE = MAXIMUM Value per Primary Key Oracle SQL Developer

Question

How do I only select the highest lines per user in this example:

Output would be TED, PEARS and BILL, ORANGE

If a new line is added to Bill, in the future, (LINE 5) I would want the same query to pull LINE 5 Communication.

Answer 1

If you want just the user and the communication, use keep :

select usr, 
    max(communication) keep(dense_rank first order by line desc) as communication
from mytable
group by usr

If you want entire rows, window functions are more appropriate:

select *
from (
    select t.*, row_number() over(partition by usr order by line desc) rn
    from mytable t
) t
where rn = 1

Side note: user is a reserved word, hence a poor choice for a column name. I used usr in the queries instead.

Answer 2

You have a column line in your table so you can use max analytical function or not exists as follows:

Using sum analytical function:

Select * from
(Select t.*, max(line) over (partition by user) as mxline
  From your_table t)
Where line = mxline

Using not exists

Select * from your_table t
Where not exists 
(Select 1 from your_table tt
Where t.user = tt.user
And tt.line > t.line)