出错啦！
错误信息：Unknown column 'xl' in 'order clause'
错误编号：1054
SQL语句：select count(*) from pro_co where pass='yes' and lm in (46,142,149,148,147,521,522,153,525,524,523,159,158,157,156,520,526,528,529,530,531,532,533) order by xl = 'desc'