strict=True breaks date parsing from json (works in pydantic)

[JacobHayes]

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Example Code

from datetime import date

from pydantic import BaseModel, ConfigDict
from sqlmodel import SQLModel

json = '{"value": "1970-01-01"}'


class Pydantic(BaseModel):
    value: date


class PydanticStrict(Pydantic):
    model_config = ConfigDict(strict=True)


class SQL(SQLModel):
    value: date


class SQLStrict(SQL):
    model_config = ConfigDict(strict=True)  # validation fails


for model in [Pydantic, PydanticStrict, SQL, SQLStrict]:
    print(f"{model.__name__}: {model.model_validate_json(json)}\n")

Description

SQLModels fails to validate json data with a date field into a model with model_config = {"strict": True}. Pydantic validates the same data correctly. For example, here's the output of the script above:

Pydantic: value=datetime.date(1970, 1, 1)

PydanticStrict: value=datetime.date(1970, 1, 1)

SQL: value=datetime.date(1970, 1, 1)

Traceback (most recent call last):
  File "/Users/jacobhayes/src/github.com/the-strawhecker-group/backend/x.py", line 26, in <module>
    print(f"{model.__name__}: {model.model_validate_json(json)}\n")
                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/jacobhayes/src/github.com/the-strawhecker-group/backend/.venv/lib/python3.12/site-packages/pydantic/main.py", line 538, in model_validate_json
    return cls.__pydantic_validator__.validate_json(json_data, strict=strict, context=context)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
pydantic_core._pydantic_core.ValidationError: 1 validation error for SQLStrict
value
  Input should be a valid date [type=date_type, input_value='1970-01-01', input_type=str]
    For further information visit https://errors.pydantic.dev/2.6/v/date_type

I haven't confirmed but my hunch is that SQLModel might be "removing" the quotes around the date string before passing into Pydantic in this case, eg: it's sending '1970-01-01' instead of valid json like '"1970-01-01"'. I think it's actually that the model_validate method defers to the sqlmodel_validate compat helper func, which just calls cls.__pydantic_validator__.validate_python instead of cls.__pydantic_validator__.validate_json. As noted in the pydantic docs, json validation in strict mode is still a bit more flexible to accommodate the limited json types (eg: no native date, etc).

Operating System

macOS

Operating System Details

No response

SQLModel Version

0.0.16

Python Version

Python 3.12.1

Additional Context

No response

[JacobHayes]

I'm hoping to fix this in #818

[ta-soft]

I wonder if there is a relationship of this to #824