How to find the max value without subquery - sql

Question

To get the below result set I wrote following SQL:
SELECT t1.FilmName,
t2.CountryName,
t1.FilmRunTimeMinutes
FROM Film as t1
INNER JOIN country as t2 on t1.FilmCountryId = t2.CountryID
WHERE t1.FilmRunTimeMinutes = ( SELECT max(t2.FilmRunTimeMinutes)
FROM film as t2
WHERE t2.FilmCountryId = t1.FilmCountryId
)
ORDER BY FilmRunTimeMinutes DESC
I read this Link and tried the same method but I could not. So how can I get the same result set using by LEFT OUTER JOIN?
Film table has those columns:
FilmId --PK
FilmName
FilmCountryId --FK
FilmRunTimeMinutes
Country table has those columns:
CountryId --PK
CountryName
Thanks in advance.

Answer 1

use Row_Number window function
SELECT TOP 1 WITH ties t1.FilmName,
t2.CountryName,
t1.FilmRunTimeMinutes
FROM Film AS t1
INNER JOIN country AS t2
ON t1.FilmCountryId = t2.CountryID
ORDER BY Row_number() OVER(partition BY FilmCountryId ORDER BY FilmRunTimeMinutes DESC),
FilmRunTimeMinutes DESC;
or use CTE/Sub-Select
WITH cte
AS (SELECT t1.FilmName,
t2.CountryName,
t1.FilmRunTimeMinutes,
Rn = Row_number() OVER(partition BY FilmCountryId ORDER BY FilmRunTimeMinutes DESC)
FROM Film AS t1
INNER JOIN country AS t2
ON t1.FilmCountryId = t2.CountryID)
SELECT *
FROM cte
WHERE Rn = 1
ORDER BY FilmRunTimeMinutes DESC
if you really want left join approach then
SELECT t1.FilmName,
t2.CountryName,
t1.FilmRunTimeMinutes
FROM Film AS t1
INNER JOIN country AS t2
ON t1.FilmCountryId = t2.CountryID
LEFT JOIN Film AS t3
ON t3.FilmCountryId = t2.CountryID
AND t3.FilmRunTimeMinutes > t1.FilmRunTimeMinutes
WHERE t3.FilmID IS NULL
ORDER BY FilmRunTimeMinutes DESC

Answer 2

Try This
;WITH Q
AS
(
SELECT
RN = ROW_NUMBER() OVER(PARTITION BY t1.FilmCountryId ORDER BY t2.FilmRunTimeMinutes DESC),
t1.FilmName,
t2.CountryName,
t1.FilmRunTimeMinutes
FROM Film as t1
INNER JOIN country as t2 on t1.FilmCountryId=t2.CountryID
ORDER BY FilmRunTimeMinutes DESC
)
SELECT
*
FROM Q
WHERE RN = 1