Unable to validate models through SQLModel.from_orm(...).

[jymchng]

First Check

• I added a very descriptive title here.
• I used the GitHub search to find a similar question and didn't find it.
• I searched the SQLModel documentation, with the integrated search.
• I already searched in Google "How to X in SQLModel" and didn't find any information.
• I already read and followed all the tutorial in the docs and didn't find an answer.
• I already checked if it is not related to SQLModel but to Pydantic.
• I already checked if it is not related to SQLModel but to SQLAlchemy.

Commit to Help

• I commit to help with one of those options 👆

Example Code

from typing import List, Optional, Any
from sqlmodel import Field, SQLModel as _SQLModel, Relationship
from slugify import slugify
from datetime import date, datetime
from pydantic import validator
from sqlalchemy.orm import declared_attr

class SQLModel(_SQLModel):
    
    @declared_attr  # type: ignore
    def __tablename__(cls) -> str:
        return cls.__name__
    
    class Config:
        use_enum_values = True

class BaseIDModel(SQLModel):
    id: Optional[int] = Field(
        primary_key=True,
        index=True,
        nullable=False,
    )

class ProjectBase(SQLModel):
    is_active: bool = Field(default=True, nullable=False)
    name: str = Field(nullable=False)

    publish_date: date = Field(
        default_factory=datetime.now().date, nullable=False)
    repr_name: Optional[str] = Field(default=None, nullable=False)
    
    approved: bool = Field(default=False, nullable=False)
    featured: bool = Field(default=False, nullable=False)  

    # post_init
    @validator("repr_name", pre=True, always=True)
    def slugify_name(cls, v, values) -> str:
        if v is None:
            print(f"{v=}, {values=}")
            return slugify(values["name"], separator="_")
        raise ValueError(
            f"`repr_name` cannot be passed in as a parameter to the `Request`.")
    
class Project(BaseIDModel, ProjectBase, table=True):
    pass

class IProjectCreate(ProjectBase):
    pass

if __name__ == '__main__':
    Project.from_orm(IProjectCreate(name='Hello A'))

Description

• There is a BaseIDModel which does nothing but provides a id field for other models to inherit from.
• The ProjectBase functions like HeroBase in the tutorials/documentations, providing the essential fields to the eventual table.
• The Project is a table.
• The IProjectCreate is a schema (pydantic's model) for the creation of Project object via an API.
• The repr_name field is a slugified representation of the name field in ProjectBase.
• My objective is to have the repr_name properly slugified before insertion into the database.
• After the creation of IProjectCreate(name='Hello A') which is handled by the API (not shown but easily appreciated), the codes call Project.from_orm(IProjectCreate(name='Hello A')) to convert the schema object into a database-orm object.
• However, it fails because in the slugify_name(..., values), the values dictionary does not contain the key name.
• Here is the output:

v=None, values={'is_active': True, 'name': 'Hello A', 'publish_date': datetime.date(2023, 2, 18)}
v=None, values={'is_active': True, 'publish_date': datetime.date(2023, 2, 18)}
---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
<ipython-input-4-8a711b7fe15b> in <module>
----> 1 Project.from_orm(IProjectCreate(name='Hello A'))

~\AppData\Roaming\Python\Python38\site-packages\sqlmodel\main.py in from_orm(cls, obj, update)
    549             # If table, create the new instance normally to make SQLAlchemy create
    550             # the _sa_instance_state attribute
--> 551             m = cls()
    552         values, fields_set, validation_error = validate_model(cls, obj)
    553         if validation_error:

<string> in __init__(__pydantic_self__, **data)

~\AppData\Roaming\Python\Python38\site-packages\sqlalchemy\orm\state.py in _initialize_instance(*mixed, **kwargs)
    480         except:
    481             with util.safe_reraise():
--> 482                 manager.dispatch.init_failure(self, args, kwargs)
    483 
    484     def get_history(self, key, passive):

~\AppData\Roaming\Python\Python38\site-packages\sqlalchemy\util\langhelpers.py in __exit__(self, type_, value, traceback)
     68             self._exc_info = None  # remove potential circular references
     69             if not self.warn_only:
---> 70                 compat.raise_(
     71                     exc_value,
     72                     with_traceback=exc_tb,

~\AppData\Roaming\Python\Python38\site-packages\sqlalchemy\util\compat.py in raise_(***failed resolving arguments***)
    206 
    207         try:
--> 208             raise exception
    209         finally:
    210             # credit to

~\AppData\Roaming\Python\Python38\site-packages\sqlalchemy\orm\state.py in _initialize_instance(*mixed, **kwargs)
    477 
    478         try:
--> 479             return manager.original_init(*mixed[1:], **kwargs)
    480         except:
    481             with util.safe_reraise():

~\AppData\Roaming\Python\Python38\site-packages\sqlmodel\main.py in __init__(__pydantic_self__, **data)
    496         # Uses something other than `self` the first arg to allow "self" as a
    497         # settable attribute
--> 498         values, fields_set, validation_error = validate_model(
    499             __pydantic_self__.__class__, data
    500         )

~\AppData\Roaming\Python\Python38\site-packages\pydantic\main.cp38-win_amd64.pyd in pydantic.main.validate_model()

~\AppData\Roaming\Python\Python38\site-packages\pydantic\fields.cp38-win_amd64.pyd in pydantic.fields.ModelField.validate()

~\AppData\Roaming\Python\Python38\site-packages\pydantic\fields.cp38-win_amd64.pyd in pydantic.fields.ModelField._apply_validators()

~\AppData\Roaming\Python\Python38\site-packages\pydantic\class_validators.cp38-win_amd64.pyd in pydantic.class_validators._generic_validator_cls.lambda5()

<ipython-input-2-8fd04dce0748> in slugify_name(cls, v, values)
     31         if v is None:
     32             print(f"{v=}, {values=}")
---> 33             return slugify(values["name"], separator="_")
     34         raise ValueError(
     35             f"`repr_name` cannot be passed in as a parameter to the `Request`.")

KeyError: 'name'

Operating System

Windows

Operating System Details

Local machine is Windows but running the FastAPI application via docker, i.e. Linux OS.

SQLModel Version

'0.0.6'

Python Version

Python 3.10.6

Additional Context

No response

[jymchng]

jonra1993/fastapi-alembic-sqlmodel-async#46 The same issue is also mentioned here.

[jymchng]

Hey, anyway I fixed my issue by noticing that validations belong to pydantic's "schema" instead of sqlalchemy's "model", hence, the @validator decorator should be applied to validating methods belong to the schemas classes, instead of models classes.

[jonra1993]

I see it is also mentioned here #68