0
我正在編寫我的第一個Python Web應用程序,並且我想使用alembic來處理遷移。到目前爲止,我已經完成了這個工作(只是指出了imp文件),它似乎並不奏效。Python 2.7中集成龍捲風(4.4.1),sqlalchemy(1.1.0)和alembic(0.8.7)
項目結構:
project/
alembic.ini
alembic/
versions/
3cd4a4f9cdef_create_users_table.py
models/
__init__.py
base.py
users.py
3cd4a4f9cdef_create_users_table.py
"""create users table
Revision ID: 3cd4a4f9cdef
Revises:
Create Date: 2016-09-07 13:54:25.705084
"""
# revision identifiers, used by Alembic.
revision = '3cd4a4f9cdef'
down_revision = None
branch_labels = None
depends_on = None
from alembic import op
import sqlalchemy as sa
def upgrade():
op.create_table(
'users',
Column('id', sa.Integer, primary_key=True),
Column('name', sa.String(256), nullable=False)
)
def downgrade():
op.drop_table('users')
__init__.py
from sqlalchemy import create_engine
from sqlalchemy.sql import select
from users import User
engine = create_engine('sqlite:///:memory:', echo=True)
base.py
from sqlalchemy.ext.declarative import declarative_base
Base = declarative_base()
users.py
from base import Base
class User(Base):
user_table = 'users'
__table__ = user_table
id = user_table.c.id
name = user_table.c.name
$ python models/__init__.py
拋出這個錯誤:
Traceback (most recent call last):
File "models/__init__.py", line 3, in <module>
from users import User
File "/Users/sudeep.agarwal/src/project/models/users.py", line 5, in <module>
class Asset(Base):
File "/Users/sudeep.agarwal/src/squiddy/models/users.py", line 10, in Asset
id = asset_table.c.id
AttributeError: 'str' object has no attribute 'c'
我不想做這users.py因爲這將意味着架構定義的重複:
from base import Base
from sqlalchemy import Column
class User(Base):
__table__ = 'users'
id = Column('id', Integer, primary_key=True)
name = Column('name', String, nullable=False)
達到此目的最簡潔的方法是什麼?
沒有工作。同樣的錯誤。 – draxxxeus
我已經更新了答案。 –
嘿,謝謝。我將代碼更改爲您建議的第一種方法(使用user_schema變量),並使用alembic的自動生成開關來生成遷移。現在就像魅力一樣。 – draxxxeus