DENSE_RANK() without duplication

Question

Here\'s what my data looks like:

| col1 | col2 | denserank | whatiwant |
|------|------|-----------|-----------|
| 1    | 1    | 1         | 1         |
| 2          


        

Answer 1

Here is one way using SUM OVER(Order by) window aggregate function

SELECT col1,Col2,
       Sum(CASE WHEN a.prev_val = a.col2 THEN 0 ELSE 1 END) OVER(ORDER BY col1) AS whatiwant 
FROM   (SELECT col1,
               col2,
               Lag(col2, 1)OVER(ORDER BY col1) AS prev_val
        FROM   Yourtable) a
ORDER  BY col1; 

How it works:

LAG window function is used to find the previous col2 for each row ordered by col1

SUM OVER(Order by) will increment the number only when previous col2 is not equal to current col2