[SQL simple question] leetcode 627. change gender

LeetCode 627. Changing gender

https://leetcode.cn/problems/swap-salary/
Please write a SQL Query to exchange all 'f' and 'm' （ namely , Will all 'f' Turn into 'm' , vice versa ）, Use only Single update sentence , And there is no intermediate temporary table .

Be careful , You must use only one update sentence , And You can't Use select sentence .

Input ：

Salary  surface ：
+----+------+-----+--------+
| id | name | sex | salary |
+----+------+-----+--------+
| 1  | A    | m   | 2500   |
| 2  | B    | f   | 1500   |
| 3  | C    | m   | 5500   |
| 4  | D    | f   | 500    |
+----+------+-----+--------+

Output ：

+----+------+-----+--------+
| id | name | sex | salary |
+----+------+-----+--------+
| 1  | A    | f   | 2500   |
| 2  | B    | m   | 1500   |
| 3  | C    | f   | 5500   |
| 4  | D    | m   | 500    |
+----+------+-----+--------+

Solution

Addition and subtraction

UPDATE Salary SET sex = char(ascii('m') + ascii('f') - ascii(sex));

Exclusive or law

UPDATE Salary SET sex = char(ascii(sex) ^ ascii('m') ^ ascii('f'));

if Function judgment statement

UPDATE Salary SET sex = IF(sex='f', 'm', 'f');

case-when-then-else-end sentence

UPDATE Salary SET 
sex = 
    CASE sex
        WHEN 'm' THEN 'f'
        WHEN 'f' THEN 'm'
        ELSE 'else'
    END;