It's surprising that mySQL would activate trademark protection for the term "mysql" because so many service providers offer mySQL, but that's their right. I'd just use "SQL" in your ad, rather than "MySql".
Very easy to get round this, post at seroundtable about just dropping the MY from the ad and its still pretty recognizable
I second dylan jones - you can still bid on the 'mySQL' phrase, just that you can't use it in the ad - cutting off the my shouldn't affect CTR too badly (especially as I would think most people who type in MySQL do know a little bit and will know to click on SQL anyway)
The Google Trademark ban only applies to the headline and description of the ad. You can use MySQL on the display url through. Try it and it will work
Trademarks are a bit of a pain in Adwords. Did you know that all sports leagues have trademarked teams' names? You can't have in your ad "LA Dodgers Tickets" for example. The trademark owner can exempt some sites so you might see such ads for large ticket selling sites. Two ways around it for the little people: 1. Use the dynamic keyword insertion feature. 2. Put the trademark term as part of your display URL such as mywebsite.com/MySQL or MySQL.mywebsite.com