if you have an error, connection is undefined.
Merge pull request #43 from zzhouj/master

fix SQL syntax Error of GROUP BY after ORDER BY (mysql 5.6.13)
Merge pull request #42 from Hiro-Nakamura/master

if you have an error, connection is undefined.
0.9.3
Merge pull request #1 from balderdashy/master

sync to 0.9.3