Nested table models not parsing correctly with pydantic v2

[brianmcburney]

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Example Code

from datetime import datetime

from pydantic import BaseModel
from sqlmodel import Field, SQLModel


class Bar(SQLModel):
    id: int = Field(primary_key=True)
    dt: datetime | None = None


class BarTable(SQLModel, table=True):
    id: int = Field(primary_key=True)
    dt: datetime | None = None


class Foo(BaseModel):
    items: list[Bar]


class FooTable(BaseModel):
    items: list[BarTable]


data = {"items": [{"id": 0, "dt": datetime.now().isoformat()}]}

# intentionally using parse_obj so it can be run against both pydantic v1 and v2

parsed = Foo.parse_obj(data)
print(parsed.items[0].dt.__class__)
# <class 'datetime.datetime'>

parsed_table = FooTable.parse_obj(data)
print(parsed_table.items[0].dt.__class__)
# pydantic v1: <class 'datetime.datetime'>
# pydantic v2: <class 'str'>

parsed_item = BarTable.parse_obj(data["items"][0])
print(parsed_item.dt.__class__)
# <class 'datetime.datetime'>

Description

The code sample is runnable against both pydantic v1 and v2.

When a table model is nested inside a BaseModel, it is not parsed correctly with pydantic v2 installed. In the example, the datetime field is a string on the parsed_table instance, not a datetime object.

In the v1 codepath, the data is parsed here. This doesn't happen in v2 path, possibly because validate_model is no longer exported from pydantic?

Is this a bug, or should I avoid nesting table models like this going forward?

Operating System

macOS

Operating System Details

No response

SQLModel Version

0.0.14

Python Version

3.11.6

Additional Context

No response