Sql max trophy count - sql

Question

I Create DataBase in SQL about Basketball. Teacher give me the task, I need print out basketball players from my database with the max trophy count. So, I wrote this little bit of code:
select surname ,count(player_id) as trophy_count
from dbo.Players p
left join Trophies t on player_id=p.id
group by p.surname
and SQL gave me this:
but I want, that SQL will print only this:
I read info about select in selects, but I don't know how it works, I tried but it doesn't work.

Answer 1

Use TOP:
SELECT TOP 1 surname, COUNT(player_id) AS trophy_count -- or TOP 1 WITH TIES
FROM dbo.Players p
LEFT JOIN Trophies t
ON t.player_id = p.id
GROUP BY p.surname
ORDER BY COUNT(player_id) DESC;
If you want to get all ties for the highest count, then use SELECT TOP 1 WITH TIES.

Answer 2

;WITH CTE AS
(
select surname ,count(player_id) as trophy_count
from dbo.Players p
group by p.surname;
)
select *
from CTE
where trophy_count = (select max(trophy_count) from CTE)
While select top with ties works (and is probably more efficient) I would say this code is probably more useful in the real world as it could be used to find the max, min or specific trophy count if needed with a very simple modification of the code.
This is basically getting your group by first, then allowing you to specify what results you want back. In this instance you can use
max(trophy_count) - get the maximum
min(trophy_count) - get the minimum
# i.e. - where trophy_count = 3 - to get a specific trophy count
avg(trophy_count) - get the average trophy_count
There are many others. Google "SQL Aggregate functions"

Answer 3

You will eventually go down the rabbit hole of needing to subsection this (examples are by week or by league). Then you are going to want to use windows functions with a cte or subquery)
For your example:
;with cte_base as
(
-- Set your detail here (this step is only needed if you are looking at aggregates)
select surname,Count(*) Ct
left join Trophies t on player_id=p.id
group by p.surname
, cte_ranked as
-- Dense_rank is chosen because of ties
-- Add to the partition to break out your detail like by league, surname
(
select *
, dr = DENSE_RANK() over (partition by surname order by Ct desc)
from cte_base
)
select *
from cte_ranked
where dr = 1 -- Bring back only the #1 of each partition
This is by far overkill but helping you lay the foundation to handle much more complicated queries. Tim Biegeleisen's answer is more than adequate to answer you question.