(str, Enum) fields are no longer (automatically) treated as strings in SQL

[nayaverdier]

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Example Code

from enum import Enum
from sqlmodel import SQLModel, Field

class SomeEnum(str, Enum):
    FOO = "FOO"
    BAR = "BAR"

class SomeModel(SQLModel, table=True):
    some_enum: SomeEnum = Field(primary_key=True)

# `SomeModel.some_enum.type` is the following
# Enum('FOO', 'BAR', name='someenum')

# in previous versions, the type was:
# AutoString()

Description

Prior to 0.0.9, all of my str, Enum types were utilizing AutoString and stored as varchars in postgres. Since #669, these types are now converted to postgres Enum fields, which is not desirable for my use case.

A very hacky workaround I found is to monkeypatch sa_Enum in the sqlmodel.main module, which works since I am not using sqlalchemy.Enum fields anywhere:

from sqlmodel import main as _sqlmodel_main

_sqlmodel_main.sa_Enum = lambda _: _sqlmodel_main.AutoString  # type: ignore

I know another solution is to override every enum field with a sqlmodel.Field(sa_column=...), but I'd prefer a global solution to treat all (str, Enum) types as AutoString instead of sqlalchemy.Enum.

Operating System

Linux

Operating System Details

No response

SQLModel Version

0.0.12

Python Version

3.11.5

Additional Context

No response

[antont]

Could there maybe be a generic solution for overriding the default mappings from python types to sql?

BTW we were using postgres string enums, and maybe it's a good default, but I figure not using them is a valid usecase too.

[emilhdiaz]

This change in the handling of Enums is a breaking change for existing schemas that previously used the VARCHAR field to store python Enums. The previous values (the python Enum values) aren't compatible with the new database Enum values (derived from the python Enum names). This forces projects to add additional migration steps to map the existing values or modify code to use the ChoiceType from sqlalchemy_utils.

Would love to see a simple (and supported) way to change default mappings

[gvoysey]

Just got nailed by this on an upgrade branch (brought about by other dependencies forcing pydantic v2).

Any resolution or tips/tricks in the past 10 months?