# 178. Rank Scores

> Nguồn: https://tiennhm.io.vn/docs/leetcode/database/178-rank-scores
> Write a solution to find the rank of the scores.

## Giới thiệu bài toán

Chi tiết: https://leetcode.com/problems/rank-scores/

Table: `Scores`

| Column Name | Type    |
| ----------- | ------- |
| id          | int     |
| score       | decimal |

- `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.

> **Tip: Yêu cầu**
>
> 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:

| id | score |
| -- | ----- |
| 1  | 3.50  |
| 2  | 3.65  |
| 3  | 4.00  |
| 4  | 3.85  |
| 5  | 4.00  |
| 6  | 3.65  |

- Output:

| score | rank |
| ----- | ---- |
| 4.00  | 1    |
| 4.00  | 1    |
| 3.85  | 2    |
| 3.65  | 3    |
| 3.65  | 3    |
| 3.50  | 4    |

## Giải quyết bài toán

```sql
SELECT
    score,
    DENSE_RANK() OVER (ORDER BY score DESC) AS 'rank'
FROM Scores;
```

Tham khảo: https://leetcode.com/submissions/detail/1039361107/