SQLModel seems to disable @model_validator when initialized with table=true

[eric-pa]

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Example Code

from sqlmodel import SQLModel, Field
from pydantic import model_validator

class SQLModelTest(SQLModel, table=True):
    id: str = Field(primary_key=True)

    @model_validator(mode="before")
    @classmethod
    def test(cls, data):
        print("Hello from sqlmodel")
        return data

sqlmodel_test = SQLModelTest(id="123")

Description

Hi,

I'm having problems migrating to pydantic v2. I have some logic in @root_validator for data that should be stored in the database. However, when using pydantic v2 and SQLModel with table=True the new @model_validator is not called. Everything works fine when table=False.

Is this a bug or am I doing something wrong?

Best
Eric

Operating System

Linux

Operating System Details

No response

SQLModel Version

0.0.14

Python Version

Python 3.12.1

Additional Context

No response

[rt87]

Same for me (with version 0.0.22)

[monchin]

I also found this bug and made a PR to fix it in #1041 but no responses so far.

For now, I found that your_obj = YourModel.model_validate(your_dict) would enable pydantic validation. In this discussion, it would be sqlmodel_test = SQLModelTest.model_validate({"id": "123"})

[mg3146]

I've tried this, but I'm getting "object has no attribute '_sa_instance_state'" errors in some of my model_validators

[iloveitaly]

Has anyone found a workaround here?

[monchin]

but I'm getting "object has no attribute '_sa_instance_state'" errors in some of my model_validators

Would you offer an example to reproduce it?

[sr-verde]

I have the same problem.

AttributeError: 'Domain' object has no attribute '_sa_instance_state'

This would be an example for it:

class DomainBase(SQLModel):
    domain: str = Field(unique=True, index=True)

class Domain(DomainBase, table=True):
    id: int | None = Field(default=None, primary_key=True)
    hashed_domain: str | None = Field(default=None, unique=True, index=True)

    @model_validator(mode="after")
    def set_hashed_domain(self) -> Self:
        self.hashed_domain = "hashed"

        return self

The issue will disappear when you remove self.hashed_domain = "hashed". My workaround is to use a mode="before". For me, it’s okay but that may not work for other use cases.

[MattOates]

Not sure if this is still an issue or not, but I found this searching for the same problem. We found this is related to some kind of lazy evaluation of the validator. If you edit any one member of the model before inspecting it then you do see the model level validation happening. Feels relatively bug like as you'd expect at init time or shortly after for this to happen and not require any further editing of data. Hope this helps someone.