That was another correct answer! Okay, let's review what we've learned in this part:
- The most basic usage of ranking functions is:
RANK() OVER(ORDER BY column1, column2...).
- The ranking functions we have learned:
RANK() - returns the rank (a number) of each row with respect to the sorting specified within parentheses.
DENSE_RANK() - returns a 'dense' rank, i.e. there are no gaps in numbering.
ROW_NUMBER() - returns a unique rank number, so even rows with the same value get consecutive numbers.
NTILE(x) - distributes the rows into a specific number of groups, provided as x.
- To get col1 of the row with rank place1 in a ranking sorted by col2, write:
WITH ranking AS
RANK() OVER (ORDER BY col2) AS RANK,
WHERE RANK = place1;
Alright, it's time for a short quiz!