WINDOW FUNCTION DENSE_RANK

description

The DENSE_RANK() function is used to represent rankings. Unlike RANK(), DENSE_RANK() does not have vacancies. For example, if there are two parallel 1s, the third number of DENSE_RANK() is still 2, and the third number of RANK() is 3.

1. DENSE_RANK() OVER(partition_by_clause order_by_clause)

example

Group by the property column to rank column x:

1. select x, y, dense_rank() over(partition by x order by y) as rank from int_t;

3. | x  | y    | rank     |
4. |----|------|----------|
5. | 1  | 1    | 1        |
6. | 1  | 2    | 2        |
7. | 1  | 2    | 2        |
8. | 2  | 1    | 1        |
9. | 2  | 2    | 2        |
10. | 2  | 3    | 3        |
11. | 3  | 1    | 1        |
12. | 3  | 1    | 1        |
13. | 3  | 2    | 2        |

keywords

1. WINDOW,FUNCTION,DENSE_RANK