Grouping results in sql query by a field in the result

Question

I have a table with the following format:

User | Entity | ID
123    AB       1
123    AB       2
543    BC       3
098    CB       4
543    BC       5
543    ZG       6

etc...

I want to get a result set that only returns the User/Entity pairs and their ID for the greatest ID, so this result for example:

User | Entity | ID
123    AB        2
098    CB        4
543    BC        5
543    ZG        6

Is there any way to do this in SQL?

Answer 1

Try to use group by with max function

select user, Entity, max(id) as id
from table 
group by user, Entity

Answer 2

You can also use CTE and Partition By

Like this:

;WITH CTE as
(
SELECT
    Users,Entity,
    ROW_NUMBER() OVER(PARTITION BY Entity ORDER BY ID DESC) AS Row,
    Id
    FROM Item
)
SELECT Users, Entity, Id From CTE Where Row = 1

Note that we used Order By ID DESC as we need highest ID . You can delete DESC if you want the smallest ID .

SQLFiddle: http://sqlfiddle.com/#!3/1dcb9/4