Rank with current order - sql

Question

I have table like this:
col1 | col2
__________________
15077244 | 544648
15077320 | 544648
15080285 | 544632
15382858 | 544648
15584221 | 544648
15584222 | 544648
15584223 | 544628
15584224 | 544628
15584225 | 544628
15584226 | 544628
15584227 | 544632
15584228 | 544632
And I want to rank it as the col2 value changed as in example below (This one is that I want to achieve):
col1 | col2 | rank
________________________
15077244 | 544648 | 1
15077320 | 544648 | 1
15080285 | 544632 | 2
15382858 | 544648 | 1
15584221 | 544648 | 1
15584222 | 544648 | 1
15584223 | 544628 | 3
15584224 | 544628 | 3
15584225 | 544628 | 3
15584226 | 544628 | 3
15584227 | 544632 | 2
15584228 | 544632 | 2
I found an answer that suggest me to use DENSE_RANK() function. So I use it:
SELECT col1, col2, DENSE_RANK() OVER(ORDER BY col2) as rank
FROM myTable
but when I use it it change the order of col1, like this:
col1 | col2 | rank
____________________________
15584223 | 544628 | 1
15584224 | 544628 | 1
15584225 | 544628 | 1
15584226 | 544628 | 1
15080285 | 544632 | 2
15584227 | 544632 | 2
15584228 | 544632 | 2
15077244 | 544648 | 3
15077320 | 544648 | 3
15382858 | 544648 | 3
15584221 | 544648 | 3
15584222 | 544648 | 3
Now when I use ORDER BY at the end of my SELECT query like ORDER BY col1, I have data with correct order but RANKS are wrong, becouse for example col2 value 544648 has RANK 3 but it should have RANK 1.
How to use DENSE_RANK function or something different that helps me RANK my col2 values without changing an data order?

Answer 1

You need to change your order for dense_rank to desc. And order the results by col1 asc.
Fiddle Demo
SELECT
col1
, col2
, DENSE_RANK() OVER(ORDER BY col2 DESC) as rank
FROM myTable
ORDER BY col1 ASC

Answer 2

While there may be an easier solution, here's one approach using a subquery with row_number to establish a grouping of results, ordering by min(col1):
SELECT t.col1, t.col2, t2.rank
FROM myTable t JOIN (
SELECT MIN(col1) minCol1, col2, ROW_NUMBER() OVER (ORDER BY MIN(col1)) rank
FROM myTable
GROUP BY col2
) t2 ON t.col2 = t2.col2
ORDER BY t.col1
Sample Demo

Answer 3

You can use a correlated subquery that with a windowed minimum.
;WITH CorrelatedDistinctCount AS
(
SELECT
D.col1,
D.col2,
(
SELECT
COUNT(DISTINCT(X.col2))
FROM
Data X
WHERE
X.col1 <= D.col1) AS DistinctCol2Count
FROM
Data D
)
SELECT
C.col1,
C.col2,
MIN(C.DistinctCol2Count) OVER (PARTITION BY C.col2) AS rank
FROM
CorrelatedDistinctCount C
ORDER BY
C.col1 ASC