def get_last_tid(self):
        try:
            spec = {'tid': {'$gt': 0}}
            sort = [('tid', -1)]
            row = self.db.docs.find_one(spec, sort=sort)
        except Exception as e:
            raise DatabaseException(e)
        if row:
            return row['tid']
        return 0
def downloadNewsPage(self, strTagName=None):
        if strTagName is None:
            #未指定 tag
            lstStrObtainedTagName = self.db.fetchallCompletedObtainedTagName()
            for strObtainedTagName in lstStrObtainedTagName:
                self.downloadNewsPageWithGivenTagName(strTagName=strObtainedTagName)
        else:
            #有指定 tag 名稱
            self.downloadNewsPageWithGivenTagName(strTagName=strTagName)