improve sqlwall rule
Merge remote-tracking branch 'upstream/master'
Merge pull request #459 from cutedemons/master

improve sqlwall rule
fix blacklist bug & parameterize NULL to ?
Merge pull request #460 from cutedemons/master

fix blacklist bug & parameterize NULL to ?
modify testcase
Merge pull request #461 from cutedemons/master

modify testcase
improve parameterize sql