def delete_msg(cls, mid):
from models import Share
msg = cls.get_by(id_=mid)
sid = msg.shareid
if msg:
db.session.delete(msg)
db.session.commit()
msg = cls.get_by(shareid=sid)
if msg is None: # 当分享没有关联消息时删除
Share.delete_share(sid)
