The statistics in the MySQL field become strings, and then they are converted into numbers for sorting

if ($sort){
$order = ‘totle_hours asc’;
}else{
$order = ‘totle_hours desc’;
}
$data{[}^{\prime }dat{a}^{\prime }]=(newStudentPunchCard())->alias{(}^{\prime }{s}^{\prime })->leftJoin{(}^{\prime }his{i}_{c}hildren{c}^{\prime }{,}^{\prime }c.id=s.ci{d}^{\prime })->leftJoin{(}^{\prime }his{i}_{u}ser{u}^{\prime }{,}^{\prime }u.id=c.ui{d}^{\prime })->leftJoin{(}^{\prime }his{i}_{d}ementgroup{d}^{\prime }{,}^{\prime }d.id=c.schooli{d}^{\prime })->leftJoin{(}^{\prime }his{i}_{s}choolmoney{m}^{\prime }{,}^{\prime }m.id=c.clas{s}_i{d}^{\prime })->where($where)
->page($page,$limit)
->group(‘s.cid’)
->field(‘c.name,c.id,c.thumb_tmp,c.class_hour,c.private_class,d.title as schoolname,u.real_name,m.title as cardname,
CAST(sum(s.class_hour) AS UNSIGNED) as totle_hours,u.username’)
->order($order)
->select();

reference ：（ Exception please contact to delete ）
https://jingyan.baidu.com/article/90808022fab5dbfd91c80f35.html