sqlalchemy 循环查询表中总数量,发现查询结果都是一样解救方法
发布时间:2020-12-17 16:59:56 所属栏目:Python 来源:网络整理
导读:代码示例: import?sqlalchemyfrom?sqlalchemy?import?create_enginefrom?sqlalchemy.orm?import?sessionmakerfrom?sqlalchemy?import?funcfrom?spiderman.config?import?DB_CONN_INFOfrom?baikedb.model?import?Clusterimport?timedb_connect?=?"mysql+mysq
代码示例: import?sqlalchemy from?sqlalchemy?import?create_engine from?sqlalchemy.orm?import?sessionmaker from?sqlalchemy?import?func from?spiderman.config?import?DB_CONN_INFO from?baikedb.model?import?Cluster import?time db_connect?=?"mysql+mysqldb://{}:{}@{}:3306/{}?charset=utf8".format(DB_CONN_INFO['name'],????????????????????????????????????????????????????????????????????DB_CONN_INFO['password'],????????????????????????????????????????????????????????????????????DB_CONN_INFO['ip'],????????????????????????????????????????????????????????????????????DB_CONN_INFO['database']) engine?=?create_engine(db_connect) session?=?sessionmaker(bind=engine)() if?__name__?==?'__main__': ????while?1: ????????num?=?session.query(func.count(Cluster.id)).scalar() ????????print(time.strftime("%Y-%m-%d?%H:%M:%S",?time.localtime()),?num) ????????time.sleep(60) 问题: 每隔一分钟查询数据库的总数量是多少,发现结果都是一样 解决办法: 在每次查询数量完成之后,添加代码session.close() if?__name__?==?'__main__': ????while?1: ????????num?=?session.query(func.count(Cluster.id)).scalar() ????????print(time.strftime("%Y-%m-%d?%H:%M:%S",?num) ????????time.sleep(60) ????????session.close() (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |