Using Ranking Window Functions in MySQL: ROW_NUMBER, RANK, and DENSE_RANK

This image presents a MySQL query using three ranking window functions—ROW_NUMBER(), RANK(), and DENSE_RANK()—to rank customer payment data from the payments table. The query filters for customer numbers less than 115 and assigns a numerical rank to each row based on the customerNumber field. These functions help differentiate between strictly ordered rows, rows with tied ranks, and consecutively ranked values without gaps. The output clearly shows the difference in ranking behavior, making it a useful reference for analytical queries in data reporting and segmentation.