islands and gaps ordering issue MYSQL 8.0 - mysql

Question

I am trying to use partition by & row_number() to count consecutive duplicate values for a given date range.Essentially its attempting to capture "streaks" If there is a break in the streak the count should start over when the value occurs again.
To reproduce these results here is the code:
CREATE TABLE partion_test (
daily DATE,
response_short_name VARCHAR(10)
);
INSERT INTO `partion_test` (`daily`, `response_short_name`) VALUES
('2020-09-21', 'A'),
('2020-09-25', 'A'),
('2020-09-26', 'A'),
('2020-09-27', 'A'),
('2020-09-28', 'A'),
('2020-09-22', 'B'),
('2020-09-20', 'C'),
('2020-09-23', 'C'),
('2020-09-24', 'C');
SELECT
daily,
response_short_name
,row_number() over (partition by response_short_name order by daily) as seqnum
FROM (
select
daily,
response_short_name
FROM partion_test
order by daily limit 1000
) A;
HERE IS THE CURRENT OUTPUT
| daily | response_short_name | seqnum | |
+------------+---------------------+--------+--+
| 2020-09-21 | A | 1 | |
| 2020-09-25 | A | 2 | |
| 2020-09-26 | A | 3 | |
| 2020-09-27 | A | 4 | |
| 2020-09-28 | A | 5 | |
| 2020-09-22 | B | 1 | |
| 2020-09-20 | C | 1 | |
| 2020-09-23 | C | 2 | |
| 2020-09-24 | C | 3 | |
+------------+---------------------+--------+--+
HERE IS THE DESIRED OUTPOUT
+------------+---------------------+--------+--+
| daily | response_short_name | seqnum | |
+------------+---------------------+--------+--+
| 2020-09-20 | C | 1 | |
| 2020-09-21 | A | 1 | |
| 2020-09-22 | B | 1 | |
| 2020-09-23 | C | 1 | |
| 2020-09-24 | C | 2 | |
| 2020-09-25 | A | 1 | |
| 2020-09-26 | A | 2 | |
| 2020-09-27 | A | 3 | |
| 2020-09-28 | A | 4 | |
+------------+---------------------+--------+--+
Ive been scratching at my brain for a while on this. Any help would be appreciated

Answer 1

You can do:
select *,
row_number() over(partition by grp order by daily) as seqnum
from (
select *,
sum(inc) over(order by daily) as grp
from (
select *,
case when lag(response_short_name) over(order by daily) = response_short_name
then 0 else 1 end as inc
from partion_test
order by daily
) x
) y
order by daily
Result:
daily response_short_name inc grp seqnum
----------- -------------------- ---- ---- ------
2020-09-20 C 1 1 1
2020-09-21 A 1 2 1
2020-09-22 B 1 3 1
2020-09-23 C 1 4 1
2020-09-24 C 0 4 2
2020-09-25 A 1 5 1
2020-09-26 A 0 5 2
2020-09-27 A 0 5 3
2020-09-28 A 0 5 4
See running example at DB Fiddle:

Answer 2

Your data doesn't fit your result, so it is quite diffcult t achieve your result
CREATE TABLE partion_test (
daily DATE,
response_short_name VARCHAR(10)
);
INSERT INTO `partion_test` (`daily`, `response_short_name`) VALUES
('2020-09-21', 'A'),
('2020-09-25', 'A'),
('2020-09-26', 'A'),
('2020-09-27', 'A'),
('2020-09-28', 'A'),
('2020-09-22', 'B'),
('2020-09-20', 'C'),
('2020-09-23', 'C'),
('2020-09-24', 'C');
select `daily`,`response_short_name`,
row_number() over (partition by `response_short_name`, grp order by `daily`) as row_num
from (select t.*,
(row_number() over (order by `daily`) -
row_number() over (partition by `response_short_name` order by `daily`)
) as grp
from partion_test t
) t
ORDER BY `daily`
daily | response_short_name | row_num
:--------- | :------------------ | ------:
2020-09-20 | C | 1
2020-09-21 | A | 1
2020-09-22 | B | 1
2020-09-23 | C | 1
2020-09-24 | C | 2
2020-09-25 | A | 1
2020-09-26 | A | 2
2020-09-27 | A | 3
2020-09-28 | A | 4
db<>fiddle here