3

プロジェクトでモデル継承を使用しています。

私のモデル:

class CommentBase(Base):
    __abstract__ = True

    id = Column(Integer, primary_key=True)
    text = Column(Unicode(500))

    @declared_attr
    def user_id(cls):
        return Column(ForeignKey('user.id'))

    @declared_attr
    def user(cls):
        return relationship('User')

    def __init__(self, user_id, text):
        self.user_id = user_id
        self.text = text

class CommentOne(CommentBase):
    __tablename__ = 'comment_one'

class CommentTwo(CommentBase):
    __tablename__ = 'comment_two'

すべてのテーブルは正しく作成されますが、テーブル (他のテーブルから継承されていないものも含む) にいくつかのテスト データを入力しようとすると、エラーが発生します。

UnmappedClassError : クラス'sqlalchemy.ext.declarative.DeclarativeMeta'がマップされていません

これが私のものBaseです：

Base = declarative_base()

継承がなければ、すべてが正常に機能します。修正方法は？

事前に感謝します！

4

2 に答える 2

4

再現できません。上記のコードは、最近の 0.7 および 0.8 バージョンで正常に動作します。

from sqlalchemy import *
from sqlalchemy.orm import *
from sqlalchemy.ext.declarative import declarative_base, declared_attr

Base = declarative_base()


class CommentBase(Base):
    __abstract__ = True

    id = Column(Integer, primary_key=True)
    text = Column(Unicode(500))

    @declared_attr
    def user_id(cls):
        return Column(ForeignKey('user.id'))

    @declared_attr
    def user(cls):
        return relationship('User')

    def __init__(self, user_id, text):
        self.user_id = user_id
        self.text = text

class User(Base):
    __tablename__ = 'user'
    id = Column(Integer, primary_key=True)

class CommentOne(CommentBase):
    __tablename__ = 'comment_one'

class CommentTwo(CommentBase):
    __tablename__ = 'comment_two'


e = create_engine("sqlite://", echo=True)

Base.metadata.create_all(e)

s = Session(e)

u1 = User()
s.add(u1)
s.flush()

s.add_all([CommentOne(user_id=u1.id, text="c1"), CommentTwo(user_id=u1.id, text="c2")])
s.commit()

print s.query(CommentOne).all()

出力：

2012-08-07 18:47:10,727 INFO sqlalchemy.engine.base.Engine PRAGMA table_info("user")
2012-08-07 18:47:10,727 INFO sqlalchemy.engine.base.Engine ()
2012-08-07 18:47:10,727 INFO sqlalchemy.engine.base.Engine PRAGMA table_info("comment_one")
2012-08-07 18:47:10,727 INFO sqlalchemy.engine.base.Engine ()
2012-08-07 18:47:10,728 INFO sqlalchemy.engine.base.Engine PRAGMA table_info("comment_two")
2012-08-07 18:47:10,728 INFO sqlalchemy.engine.base.Engine ()
2012-08-07 18:47:10,728 INFO sqlalchemy.engine.base.Engine 
CREATE TABLE user (
    id INTEGER NOT NULL, 
    PRIMARY KEY (id)
)


2012-08-07 18:47:10,728 INFO sqlalchemy.engine.base.Engine ()
2012-08-07 18:47:10,729 INFO sqlalchemy.engine.base.Engine COMMIT
2012-08-07 18:47:10,729 INFO sqlalchemy.engine.base.Engine 
CREATE TABLE comment_one (
    id INTEGER NOT NULL, 
    text VARCHAR(500), 
    user_id INTEGER, 
    PRIMARY KEY (id), 
    FOREIGN KEY(user_id) REFERENCES user (id)
)


2012-08-07 18:47:10,729 INFO sqlalchemy.engine.base.Engine ()
2012-08-07 18:47:10,729 INFO sqlalchemy.engine.base.Engine COMMIT
2012-08-07 18:47:10,730 INFO sqlalchemy.engine.base.Engine 
CREATE TABLE comment_two (
    id INTEGER NOT NULL, 
    text VARCHAR(500), 
    user_id INTEGER, 
    PRIMARY KEY (id), 
    FOREIGN KEY(user_id) REFERENCES user (id)
)


2012-08-07 18:47:10,730 INFO sqlalchemy.engine.base.Engine ()
2012-08-07 18:47:10,730 INFO sqlalchemy.engine.base.Engine COMMIT
2012-08-07 18:47:10,732 INFO sqlalchemy.engine.base.Engine BEGIN (implicit)
2012-08-07 18:47:10,733 INFO sqlalchemy.engine.base.Engine INSERT INTO user DEFAULT VALUES
2012-08-07 18:47:10,733 INFO sqlalchemy.engine.base.Engine ()
/Users/classic/dev/sa07/lib/sqlalchemy/engine/default.py:463: SAWarning: Unicode type received non-unicode bind param value.
  param.append(processors[key](compiled_params[key]))
2012-08-07 18:47:10,751 INFO sqlalchemy.engine.base.Engine INSERT INTO comment_two (text, user_id) VALUES (?, ?)
2012-08-07 18:47:10,751 INFO sqlalchemy.engine.base.Engine ('c2', 1)
2012-08-07 18:47:10,753 INFO sqlalchemy.engine.base.Engine INSERT INTO comment_one (text, user_id) VALUES (?, ?)
2012-08-07 18:47:10,753 INFO sqlalchemy.engine.base.Engine ('c1', 1)
2012-08-07 18:47:10,753 INFO sqlalchemy.engine.base.Engine COMMIT
2012-08-07 18:47:10,754 INFO sqlalchemy.engine.base.Engine BEGIN (implicit)
2012-08-07 18:47:10,754 INFO sqlalchemy.engine.base.Engine SELECT comment_one.id AS comment_one_id, comment_one.text AS comment_one_text, comment_one.user_id AS comment_one_user_id 
FROM comment_one
2012-08-07 18:47:10,754 INFO sqlalchemy.engine.base.Engine ()
[<__main__.CommentOne object at 0x1014e37d0>]
于 2012-08-07T22:47:38.730 に答える