Fixed bug in example code.
Fixed bug in example code.

Akrog/sqlalchemy,davidjb/sqlalchemy,bdupharm/sqlalchemy,monetate/sqlalchemy,dstufft/sqlalchemy,Akrog/sqlalchemy,wujuguang/sqlalchemy,wfxiang08/sqlalchemy,j5int/sqlalchemy,276361270/sqlalchemy,WinterNis/sqlalchemy,inspirehep/sqlalchemy,EvaSDK/sqlalchemy,brianv0/sqlalchemy,elelianghh/sqlalchemy,dstufft/sqlalchemy,davidfraser/sqlalchemy,epa/sqlalchemy,halfcrazy/sqlalchemy,davidjb/sqlalchemy,halfcrazy/sqlalchemy,j5int/sqlalchemy,epa/sqlalchemy,olemis/sqlalchemy,pdufour/sqlalchemy,itkovian/sqlalchemy,sqlalchemy/sqlalchemy,davidfraser/sqlalchemy,itkovian/sqlalchemy,robin900/sqlalchemy,WinterNis/sqlalchemy,wfxiang08/sqlalchemy,inspirehep/sqlalchemy,bdupharm/sqlalchemy,elelianghh/sqlalchemy,276361270/sqlalchemy,monetate/sqlalchemy,graingert/sqlalchemy,olemis/sqlalchemy,sandan/sqlalchemy,brianv0/sqlalchemy,zzzeek/sqlalchemy,hsum/sqlalchemy,bootandy/sqlalchemy,ThiefMaster/sqlalchemy,wujuguang/sqlalchemy,bootandy/sqlalchemy,EvaSDK/sqlalchemy,sandan/sqlalchemy,pdufour/sqlalchemy,hsum/sqlalchemy,ThiefMaster/sqlalchemy,robin900/sqlalchemy,graingert/sqlalchemy