Question

2308. Arrange Table by Gender

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Description

Table: Genders

+-------------+---------+
| Column Name | Type  |
+-------------+---------+
| user_id   | int   |
| gender    | varchar |
+-------------+---------+
user_id is the primary key (column with unique values) for this table.
gender is ENUM (category) of type 'female', 'male', or 'other'.
Each row in this table contains the ID of a user and their gender.
The table has an equal number of 'female', 'male', and 'other'.

 

Write a solution to rearrange the Genders table such that the rows alternate between 'female', 'other', and 'male' in order. The table should be rearranged such that the IDs of each gender are sorted in ascending order.

Return the result table in the mentioned order.

The result format is shown in the following example.

 

Example 1:

Input: 
Genders table:
+---------+--------+
| user_id | gender |
+---------+--------+
| 4     | male   |
| 7     | female |
| 2     | other  |
| 5     | male   |
| 3     | female |
| 8     | male   |
| 6     | other  |
| 1     | other  |
| 9     | female |
+---------+--------+
Output: 
+---------+--------+
| user_id | gender |
+---------+--------+
| 3     | female |
| 1     | other  |
| 4     | male   |
| 7     | female |
| 2     | other  |
| 5     | male   |
| 9     | female |
| 6     | other  |
| 8     | male   |
+---------+--------+
Explanation: 
Female gender: IDs 3, 7, and 9.
Other gender: IDs 1, 2, and 6.
Male gender: IDs 4, 5, and 8.
We arrange the table alternating between 'female', 'other', and 'male'.
Note that the IDs of each gender are sorted in ascending order.

Solutions

Solution 1

# Write your MySQL query statement below
WITH
  t AS (
    SELECT
      *,
      RANK() OVER (
        PARTITION BY gender
        ORDER BY user_id
      ) AS rk1,
      CASE
        WHEN gender = 'female' THEN 0
        WHEN gender = 'other' THEN 1
        ELSE 2
      END AS rk2
    FROM Genders
  )
SELECT user_id, gender
FROM t
ORDER BY rk1, rk2;

Solution 2

SELECT
  user_id,
  gender
FROM Genders
ORDER BY
  (
    RANK() OVER (
      PARTITION BY gender
      ORDER BY user_id
    )
  ),
  2;