主页 / 问题 / 671214
Accepted
virvaldium
Asked:2020-05-26 20:41:04 +0000 UTC2020-05-26 20:41:04 +0000 UTC

在 SQLAlchemy 表中添加和修改记录

  • 772

你好！我使用 SQLAlchemy 使用数据库。创建了这个类：

Base = declarative_base()

class Pool(Base):
    """
    Управляет таблицей пулов. Создает, удаляет, возвращает список всех пулов в системе
    """
    __tablename__ = 'tbl_pool'
    id = Column(Integer, primary_key=True, autoincrement=True)
    name = Column(String(255), unique=True, nullable=False, default='default')
    description = Column(String(512))

    def __init__(self):
        self.session = BaseConnector.get_connection() # тут я получаю параметры подключения к базе

    def add_new_pool(self, pool_name='default_pool', pool_description="No description"):
        """
        Создает новую запись в таблице
        """
        self.name = pool_name
        self.description = pool_description
        try:
            self.session.add(self)
            self.session.commit()
        except IntegrityError:
            self.session.rollback()
            return 'Error! Poll exists'
        return 'Success! Poll created'

    def get_pool_list(self):
        """
        Получает список всех элементов в таблице
        """
        try:
            query_pool_list = self.session.query(Pool)
        except SQLAlchemyError:
            self.session.rollback()
            return {'error': 'error in query \"get_pool_list\"'}
        pool_dict = {}
        for pool in query_pool_list:
            pool_dict[pool.name] = pool.description
        return pool_dict

description请告诉我，根据id将作为参数（请求示例：）传递的更改字段的方法应该是UPDATE 'tbl_pool' SET description='new_description' WHERE id=10什么样的？使选择看起来像什么的方法（示例查询：）SELECT description FROM 'tbl_pool' WHERE id=10？

python

1 个回答

  1. Best Answer

    尝试向您的类添加一个方法，这里来自更新文档

    def update_description(self, id_to_update, new_desc):
    try:
        query = self.session.query(Pool).filter(Pool.id == id_to_update).\
            update({Pool.description: new_desc}, synchronize_session=False)
        self.session.commit()
    except SQLAlchemyError:
        self.session.rollback()
        return {'error': 'error'}
    return True

    我不确定以下直接分配方法有多正确：

    def update_description(self, id_to_update, new_desc):
    try:
        query = self.session.query(Pool).filter(Pool.id == id_to_update).first()
        query.description = new_desc
        self.session.commit()
    except SQLAlchemyError:
        self.session.rollback()
        return {'error': 'error'}
    return True
    • 0

相关问题