WINDOW FUNCTION ROW_NUMBER
Description
This function returns an integer for each row of each partition. The integers start from 1 and increase continuously. Unlike RANK() and DENSE_RANK(), ROW_NUMBER() does not return repeated values or leave any number vacant since the integers are continuous.
ROW_NUMBER() OVER(partition_by_clause order_by_clause)Example
select x, y, row_number() over(partition by x order by y) as rank from int_t;
| x | y | rank |
|---|------|----------|
| 1 | 1 | 1 |
| 1 | 2 | 2 |
| 1 | 2 | 3 |
| 2 | 1 | 1 |
| 2 | 2 | 2 |
| 2 | 3 | 3 |
| 3 | 1 | 1 |
| 3 | 1 | 2 |
| 3 | 2 | 3 |Keywords
WINDOW,FUNCTION,ROW_NUMBER