Analytical Functions in SQL . Part 1
Jul 1, 2021
Rank function in SQL assigns a RANK to a column value based on its weight.
To illustrate, I use the below data set that contains columns — educational courses, category, quantity sold .
Problem Statement : Rank the 10 least sold products
RANK Function
There is a tie for the 3rd, 6th and 8th spot, also there are no 4th and 7th spots
DENSE RANK Function
Use Dense Rank when you do NOT want gaps .
There is a tie for the 3rd, 5th and 6th spots however there is no gap in the sequence unlike Rank.
ROW_NUMBER Function
when you do NOT want a tie, use ROW_NUMBER
A unique rank is assigned to every row.
