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 (47,161,542,541,540,539,537,536,535,534,163,448,449,182,183,181,180,179,178) order by xl = 'desc'