LeetCode 數據庫面試題 – 交換工資（Swap Salary）

用一條 UPDATE 語句，在不使用中間臨時表的情況下，將 salary 表中 sex 的值反轉。

原題

Given a table salary, such as the one below, that has m=male and f=female values. Swap all f and m values (i.e., change all f values to m and vice versa) with a single update query and no intermediate temp table.

For example:

After running your query, the above salary table should have the following rows:

SQL

1UPDATE salary 
2SET 
3    sex = IF(sex='f', 'm', 'f');

OR

1UPDATE salary 
2SET 
3    sex = CASE sex 
4        WHEN 'f' THEN 'm' 
5        ELSE 'f' 
6    END;