Description
Describe the bug
Auto-generated PostgreSQL code in 1.13.2 contains invalid code causing migrations to fail. This appears to be around Serial columns and appears to be related to the fix implemented in: #1479. I get the log around detecting a serial and omitting it. We have a ton of tables like this, and not all of them are having this behavior. The table definitions haven't changed, and everything works in 1.13.1.
The id columns definitely have a server default set, but all of them do, not just the ones triggering this behavior. I am having trouble figuring out what is different between them. The python definition is the same, and the database definitions appear to be almost identical.
I tried replicating it in a fresh database to generate a minimum code sample, but couldn't replicate the behavior
Expected behavior
Expect no change from previous behavior.
To Reproduce
Table Definition:
class GEO(Base):
__tablename__ = "GEO"
id: Mapped[int] = mapped_column(Identity(on_null=True), primary_key=True)
name: Mapped[str] = mapped_column(String(4), unique=True)from typing import Sequence, Union
from alembic import op
import sqlalchemy as sa
# revision identifiers, used by Alembic.
revision: str = 'b6001b86cfc9'
down_revision: Union[str, None] = 'd4e45e048b78'
branch_labels: Union[str, Sequence[str], None] = None
depends_on: Union[str, Sequence[str], None] = None
def upgrade() -> None:
op.alter_column('GEO', 'id',
existing_type=sa.INTEGER(),
server_default=sa.Identity(always=False, on_null=True),
existing_nullable=False,
autoincrement=True)
def downgrade() -> None:
op.alter_column('GEO', 'id',
existing_type=sa.INTEGER(),
server_default=None,
existing_nullable=False,
autoincrement=True)Error
Generated SQL it tries to run during migration is: ALTER TABLE "GEO" ALTER COLUMN id;
Which doesn't do anything and isn't valid and throws an error.
Versions.
- OS: Docker in docker container
- Python: 3.11
- Alembic: 1.13.2
- SQLAlchemy: 2.0.31
- Database: RDS PostGRES 14.10
- DBAPI: psycopg2