MySQL Cheat Sheet
Mikiya Okuno has released a simple “MySQL Cheat Sheet” recently. It is designed for those who newly starts using MySQL or uses it occasionally. It fits one page of A4 size perfectly.
You can download it from here: http://www.mysqlpracticewiki.com/files/cheat-sheet-en.pdf.
The license is CC-BY-SA, i.e. redistribution and modifications are allowed under CC license.