This episode explores how you can create and use TRIGGERS with your MySQL tables as data protection for your tables.
A good purpose for one would be to add a last_updated timestamp field.

MySQL Course Playlist:

SQL file Code GIST: https://gist.github.com/prof3ssorSt3v3/5c8ad4bbd6d9297139d504502f6c1b2d

MySQL Trigger reference: https://dev.mysql.com/doc/refman/5.7/en/create-trigger.html