I run at least the second time into the same crazy mysql2 gem error with Ruby on Windows but I couldn’t find any solution with Google. So I came up with a revolutionary solution presented in the following.

The error message was You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use (Mysql2::Error) although I was able to successfully query my database with this query. After spending hours to identify the problem and to find a solution, I just restarted my system. That fixed everything …

Update: Another thing you should looking for are reserved keywords like order in MySQL which must be escaped by ` ` `.