sqlalchemy postgresql枚举不会在db migrate上创建类型

时间:2016-06-16 02:17:44

标签: flask sqlalchemy flask-sqlalchemy flask-migrate sqlalchemy-migrate

我在Python3下使用Flask开发了一个web应用程序。我在db migrate / upgrade上遇到postgresql枚举类型的问题。

我添加了一个列" status"建模:

class Banner(db.Model):
    ...
    status = db.Column(db.Enum('active', 'inactive', 'archive', name='banner_status'))
    ...

python manage.py db migrate生成的迁移是:

from alembic import op
import sqlalchemy as sa

def upgrade():
    op.add_column('banner', sa.Column('status', sa.Enum('active', 'inactive', 'archive', name='banner_status'), nullable=True))

def downgrade():
    op.drop_column('banner', 'status')

当我python manage.py db upgrade时,我收到错误:

...
sqlalchemy.exc.ProgrammingError: (psycopg2.ProgrammingError) type "banner_status" does not exist
LINE 1: ALTER TABLE banner ADD COLUMN status banner_status

 [SQL: 'ALTER TABLE banner ADD COLUMN status banner_status']

为什么迁移不会创建类型" banner_status"?

我做错了什么?

$ pip freeze
alembic==0.8.6
Flask==0.10.1
Flask-Fixtures==0.3.3
Flask-Login==0.3.2
Flask-Migrate==1.8.0
Flask-Script==2.0.5
Flask-SQLAlchemy==2.1
itsdangerous==0.24
Jinja2==2.8
Mako==1.0.4
MarkupSafe==0.23
psycopg2==2.6.1
python-editor==1.0
requests==2.10.0
SQLAlchemy==1.0.13
Werkzeug==0.11.9

2 个答案:

答案 0 :(得分:43)

我决定用这个问题。

我更改了迁移和迁移的代码,如下所示:

from alembic import op
import sqlalchemy as sa
from sqlalchemy.dialects import postgresql

def upgrade():
    banner_status = postgresql.ENUM('active', 'inactive', 'archive', name='banner_status')
    banner_status.create(op.get_bind())

    op.add_column('banner', sa.Column('status', sa.Enum('active', 'inactive', 'archive', name='banner_status'), nullable=True))

def downgrade():
    op.drop_column('banner', 'status')

    banner_status = postgresql.ENUM('active', 'inactive', 'archive', name='banner_status')
    banner_status.drop(op.get_bind())

现在python manage.py db upgrade\downgrade已成功执行。

答案 1 :(得分:2)

我认为这种方式更简单:

from alembic import op
import sqlalchemy as sa
from sqlalchemy.dialects import postgresql

def upgrade():
    # others_column = ...
    banner_status = postgresql.ENUM('active', 'inactive', 'archive', name='banner_status', create_type=False), nullable=False)

如果需要,还可以将postgresql.ENUM添加到您的downgrade()函数中。