Problem with updating an ENUM type in postgresql and alembic

I have an issue with ENUM in postgresql and alembic and I couldn't resolve the problem using the existing topics in the StackOverflow in this regard.

I had the following code:

from sqlalchemy.dialects.postgresql import ENUM
from enum import Enum

class StatusEnum(Enum):
    requested = "requested"
    accepted = "accepted"
    declined = "declined"

class EventModifications(BaseModel):
    __tablename__ = "event_modifications"

    old_value = Column(Text)
    new_value = Column(Text)
    status = Column(
        ENUM(StatusEnum),
        default=StatusEnum.accepted.value,
        server_default=StatusEnum.accepted.value
    )

Then I appended an entity in the Enum class and also changed the default value of status column to the new added value:

class StatusEnum(Enum):
    requested = "requested"
    accepted = "accepted"
    declined = "declined"
    modified = "modified"  # new one

class EventModifications(BaseModel):
    __tablename__ = "event_modifications"

    old_value = Column(Text)
    new_value = Column(Text)
    status = Column(
        ENUM(StatusEnum),
        default=StatusEnum.modified.value,  # changed the defaults
        server_default=StatusEnum.modified.value
    )

Error caused by Alembic:

sqlalchemy.exc.ProgrammingError: (psycopg2.errors.DatatypeMismatch) column "status" cannot be cast automatically to type statusenum
HINT:  You might need to specify "USING status::statusenum".

[SQL: ALTER TABLE event_modifications ALTER COLUMN status TYPE statusenum ]

But when I change the name of StatusEnum class to something else it works well!

You can use these queries to solve your problem

1.

ALTER TABLE "event_modifications" DROP "status";

2.

DROP TYPE "statusenum"

• note that your data will be removed and you need call alembic again to migratation.