'Creating duplicating rank over multiple columns

I have data as below where for one customer ID there are several orders (KEY) which is the primary key. I have also have a activity flag as below (either 0 or 1).

CUST_ID KEY FLAG
1       1   1
1       2   1
1       3   1
1       4   0
1       5   0
1       6   1
1       7   1
1       8   0
1       9   0

Now I want to create ranks as below based on the FLAG. The idea is to give same Rank as preceding row if the FLAG is same as preceding row. The Rank increments if the current value is different from preceding value.

CUST_ID KEY FLAG RN
1       1   1    1
1       2   1    1
1       3   1    1
1       4   0    2
1       5   0    2
1       6   1    3
1       7   1    3
1       8   0    4
1       9   0    4

I'm new to SQL, so please let me know if I need to reframe my question.

sqlrankdense-rank


Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution Source

Related Questions