$map['from_user|to_user']=session('id');
$list=db('inside_letter')->where($where)->where('to_msg_read=2 OR from_msg_read=2')->where($map)->limit($tol,$limit)->select();
$map['from_user|to_user']=session('id');
$list=db('inside_letter')->where($where)->where('to_msg_read=2 OR from_msg_read=2')->where($map)->limit($tol,$limit)->select();
https://www.bilibili.com/video/BV1k8411575T/?vd_source=d68ed178f151e80fea1e02efd205802c