Description

Table: Scores

Column NameType
idint
scoredecimal
  • id is the primary key (column with unique values) for this table.
  • Each row of this table contains the score of a game. Score is a floating point value with two decimal places.

Problem Statement

Write a solution to find the rank of the scores. The ranking should be calculated according to the following rules:

  • The scores should be ranked from the highest to the lowest.
  • If there is a tie between two scores, both should have the same ranking.
  • After a tie, the next ranking number should be the next consecutive integer value. In other words, there should be no holes between ranks.

Return the result table ordered by score in descending order.

The result format is in the following example.

Example 1:

Input: Scores table:

idscore
13.50
23.65
34.00
43.85
54.00
63.65

Output:

scorerank
4.001
4.001
3.852
3.653
3.653
3.504

Solution

The definition of rank is exactly the RANK() Window function. For this, we first need to define the window. This window is not partitioned by any field but needs to be ordered by score in descending order to assign the higher rank to larger scores.

1SELECT 
2    score, 
3    DENSE_RANK() OVER (ORDER BY score DESC) AS 'rank' 
4    FROM scores 
5    ORDER BY score DESC;