Question

我创建了以下课程这似乎使我可以访问表的架构，但不能访问表本身。我看到的大多数示例，包括手册中的示例，都遵循用于创建表的代码

class DataBase:
    def __init__(self,user, password, db, host='localhost', port=5432):
        '''Initializes the connection and a metadata objects'''
        # We connect with the help of the PostgreSQL URL
        # postgresql://federer:grandestslam@localhost:5432/tennis
        url = 'postgresql://{}:{}@{}:{}/{}'
        url = url.format(user, password, host, port, db)

        # The return value of create_engine() is our connection object
        self.engine = sqlalchemy.create_engine(url, client_encoding='utf8', echo=False)  #echo=True enable logging (This is Python loggin module)
        self.conn=self.engine.connect()
        # We then bind the connection to MetaData()
        self.meta = sqlalchemy.MetaData(bind=self.con, reflect=True)

然后我用

if __name__ == '__main__':
    db=DataBase('nme','nme','nme')   
    db.meta.tables['tablename']

但是，这使我可以访问表的架构我想在创建表后在该表中插入一条记录

编辑：此方法有效，谢谢

known_devices=Table('known_devices',self.meta,autoload=True)

        ins=known_devices.insert().values(
                      ....        
            )

        result=self.conn.execute(ins)

Answer 1

看 https://docs.sqlalchemy.org/en/latest/core/reflection.html和 https://docs.sqlalchemy.org/en/latest/core/dml.html#sqlalchemy.sql.expression.Insert.values

应该是类似

的东西

yourtable=Table('tablename', meta, autoload=True)
conn.execute(yourtable.insert(), field="content")

SQLAlchemy核心-如何访问现有的Postgresql数据库？

1 个答案: