Conditional group by with window function in Snowflake query - sql

Question

I have a table in Snowflake in following format:
create temp_test(name string, split string, value int)
insert into temp_test
values ('A','a', 100), ('A','b', 200), ('A','c',300), ('A', 'd', 400), ('A', 'e',500), ('B', 'a', 1000), ('B','b', 2000), ('B','c', 3000), ('B', 'd',4000), ('B','e', 5000)
First step, I needed only top 2 value per name (sorted on value), so I used following query to get that:
select name, split, value,
row_number() over (PARTITION BY (name) order by value desc) as row_num
from temp_test
qualify row_num <= 2
Which gives me following resultset:
NAME SPLIT VALUE ROW_NUM
A e 500 1
A d 400 2
B e 5000 1
B d 4000 2
Now, I need to sum values other than Top 2 and put it in a different Split named as "Others", like this:
NAME SPLIT VALUE
A e 500
A d 400
A Others 600
B e 5000
B d 4000
B Others 6000
How to do that in Snowflake query or SQL in general?

Answer 1

with data as (
select name, split, value,
row_number() over (partition by (name) order by value desc) as row_num
from temp_test
)
select
name,
case when row_num <= 2 then split else 'Others' end as split,
sum(value) as value
from data
group by name, case when row_num <= 2 then row_num else 3 end

Answer 2

Shawnt00's answer is good, but for the record in Snowflake this can be written simpler:
Firstly the group by at the end can refer to the results by index or name:
GROUP BY 1,2
or
GROUP BY name, split
also as the CASE only has too branches an IFF can be used and seems you are using a CTE to add the row_number you can push the IFF into the CTE also
WITH data AS (
SELECT name, value,
ROW_NUMBER() OVER (PARTITION BY name ORDER BY value DESC) AS row_num,
IFF(row_num < 3, split, 'Others') as n_split
FROM VALUES ('A','a', 100), ('A','b', 200), ('A','c',300), ('A', 'd', 400),
('A', 'e',500), ('B', 'a', 1000), ('B','b', 2000), ('B','c', 3000),
('B', 'd',4000), ('B','e', 5000)
v(name, split, value)
)
SELECT
name,
n_split,
SUM(value) AS value
FROM data
GROUP BY name, n_split;
and if super keen on small SQL push the ROW_NUMBER into the IFF:
WITH data AS (
SELECT name, value,
IFF(ROW_NUMBER() OVER (PARTITION BY name ORDER BY value DESC) < 3, split, 'Others') as n_split
FROM VALUES ('A','a', 100), ('A','b', 200), ('A','c',300), ('A', 'd', 400),
('A', 'e',500), ('B', 'a', 1000), ('B','b', 2000), ('B','c', 3000),
('B', 'd',4000), ('B','e', 5000)
v(name, split, value)
)
SELECT
name,
n_split AS split,
SUM(value) AS value
FROM data
GROUP BY name, n_split;
gives:
NAME SPLIT VALUE
A e 500
A d 400
A Others 600
B e 5000
B d 4000
B Others 6000