mysql, update <table> set <field> = case
https://leetcode.com/submissions/detail/856532337/\n\n# Write your MySQL query statement below\nupdate Salary set sex = case \n    when sex = \'m\' then \'f\'\n
https://leetcode.com/submissions/detail/856532337/\n```\n# Write your MySQL query statement below\nupdate Salary set sex = case \n    when sex = \'m\' then \'f\'\n    when sex = \'f\' then \'m\'\n    end\n```
['Ordered Set', 'MySQL']