RANK, DENSE_RANK and ROW_NUMBER

Ranking Functions

These three functions all assign a number to each row within a partition, but differ in how they handle ties.

SELECT name, score,
       ROW_NUMBER()  OVER (ORDER BY score DESC) AS row_num,
       RANK()        OVER (ORDER BY score DESC) AS rank,
       DENSE_RANK()  OVER (ORDER BY score DESC) AS dense_rank
FROM results;