Get the Whitepaper called Beyond SQLi: Obfuscate and Bypass. It discusses filter evasion, normal and advanced SQL injection bypassing techniques, and more.
You can download it from the following link: https://packetstormsecurity.com/files/download/105600/beyond-sqli.txt
Source: https://packetstormsecurity.com/files/105600/Beyond-SQLi-Obfuscate-And-Bypass.html