Repeatedly run a command and alert me to changes?

I need to monitor a DB for changes, and alert me if there is a change. I want to run a command every X seconds and compare the output, if it's different alert me via email.

I want to do something very similar to watch --diff mysql < commands.sql but instead of --diff it would send me an email to alert me.

Is there anything already out there that will do this or should I write it?