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How to write column name redirection using sqlalchemy-migrate?

I am trying to change the name of a column. The first attempt was with this script:

meta = MetaData()

users = Table('users', meta,
    Column('id', Integer, primary_key=True),
    Column('name', String(50), unique=True),
    Column('email', String(120), unique=True)
    )

def upgrade(migrate_engine):
    meta.bind = migrate_engine
    users.c.id.alter(name='id')

def downgrade(migrate_engine):
    meta.bind = migrate_engine
    users.c.id.alter(name='user_id')

Running migrate.py testin my dev (sqlite) database works as well as being updated and downgraded. But when deploying it in my test environment on Heroku (which uses PostgreSQL 8.3), I get a trace when I try to upgrade. Gist is this message:

sqlalchemy.exc.ProgrammingError: (ProgrammingError) column "id" does not exist

Then I tried using users.c.user_idin the update method. This does not work in both environments .:

AttributeError: user_id

The workaround I'm using now is the script:

meta_old = MetaData()
meta_new = MetaData()

users_old = Table('users', meta_old,
    Column('user_id', Integer, primary_key=True),
    Column('name', String(50), unique=True),
    Column('email', String(120), unique=True)
    )

users_new = Table('users', meta_new,
    Column('id', Integer, primary_key=True),
    Column('name', String(50), unique=True),
    Column('email', String(120), unique=True)
    )

def upgrade(migrate_engine):
    meta_old.bind = migrate_engine
    users_old.c.user_id.alter(name='id')

def downgrade(migrate_engine):
    meta_new.bind = migrate_engine
    users_new.c.id.alter(name='user_id')

, - sqlalchemy-migrate. . - , . , , , , DRY .

+5
3

DRY: er , . ! :

def upgrade(migrate_engine):
    meta = MetaData(bind=migrate_engine)
    users = Table('users', meta, autoload=True)
    users.c.user_id.alter(name='id')

def downgrade(migrate_engine):
    meta = MetaData(bind=migrate_engine)
    users = Table('users', meta, autoload=True)
    users.c.id.alter(name='user_id')

!

+12

:

from alembic import op
....
def upgrade(migrate_engine):
    op.alter_column('users', 'user_id', new_column_name='id')

def downgrade(migrate_engine):
    op.alter_column('users', 'id', new_column_name='user_id')
+3

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MetaData echo=True sqlalchemy.create_engine, SQL-, . , () Postgres. , .

: , Django Table . , MetaData Table factory, . / .

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+1

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