refactored genSelectSql
refactored genSelectSql

evalphobia/xorm,zileyuan/xorm,go-xorm/xorm,vCaesar/xorm,tempbottle/xorm,go-xorm/xorm,aviau/xorm,aviau/xorm,Michael2008S/xorm,evalphobia/xorm,ymhhh/xorm,zileyuan/xorm,vCaesar/xorm,Michael2008S/xorm,ymhhh/xorm,tempbottle/xorm