MySql Easy Solution
\nUPDATE salary SET sex = (CASE \nWHEN sex = \'f\' \nTHEN \'m\' \nELSE \'f\' \nEND);\n
```\nUPDATE salary SET sex = (CASE \nWHEN sex = \'f\' \nTHEN \'m\' \nELSE \'f\' \nEND);\n```
['MySQL']