update column constraint when adding enum item

[Bart Van Loon]

Describe the bug
When creating a new version script (I use Flask-Migrate), alembic reports it finds no changes in my schema when I add an item to an enum used as a column constraint.

Expected behavior
I was hoping to get a migration script with an appropriate alter_column method applied

To Reproduce

class ProblemType(IntEnum):                                                      
                                                                                   
    SPLIT = auto()                                                               
    ADD = auto()                                                                 
    SUBTRACT = auto()                                                            
    ADDSUB = auto()

and later

class ProblemSheet(DB.Model):
    
    problem_type: DB.Mapped[ProblemType] = DB.mapped_column(                     
        DB.Enum(                                                                 
            ProblemType,                                                         
            create_constraint=True,                                              
            values_callable=lambda x: [str(i.value) for i in x],                 
        )                                                                        
    ) 

now:

1. initialise the database
2. add an item to the ProblemType IntEnum
3. migrate the database

Error
No change will be detected, leaving my application in a state in which it cannot be used to add problem sheets of the new problem type.

INFO  [alembic.runtime.migration] Context impl SQLiteImpl.
INFO  [alembic.runtime.migration] Will assume non-transactional DDL.
INFO  [alembic.env] No changes in schema detected.

Versions.

• OS: x86_64 GNU/Linux
• Python: 3.9.2
• Alembic: 1.13.1
• SQLAlchemy: 2.0.25
• Database: SQLite
• DBAPI: aiosqlite

Additional context
This is a Flask app with the Flask-Migrate wrapper around alembic.

Have a nice day and a great 2024!

[Federico Caselli]

Hi

This is a duplicate of #363 and partially of #278
There is a 3rd party extension that improves thing for postgresql, I don't know if it works also for sqlite https://github.com/Pogchamp-company/alembic-postgresql-enum

[Bart Van Loon]

I see. Thanks for following this up!