Misbehaving model `save()` when names are too long

[rgabor-dev]

Describe the bug
Model save() is not working when the model name and field name is too long and select_related is used.

To Reproduce

Tortoise ORM version: 0.25.1

Creating the test models:

from tortoise.models import Model
from tortoise import fields

class TUser(Model):
    id = fields.UUIDField(primary_key=True)
    name = fields.CharField(max_length=100)

    user_information: fields.ReverseRelation["models.VeryLongNameForTestingPurposesOnlyUserInfo"]
    short_user_info: fields.ReverseRelation["models.ShortUserInfo"]


class VeryLongNameForTestingPurposesOnlyUserInfo(Model):
    id = fields.UUIDField(primary_key=True)
    user: fields.OneToOneNullableRelation[TUser] = fields.OneToOneField(
        model_name="models.TUser",
        to_field="id",
        related_name="user_information"
    )
    not_too_long_user_age = fields.IntField()


class ShortUserInfo(Model):
    id = fields.UUIDField(primary_key=True)
    user: fields.OneToOneNullableRelation[TUser] = fields.OneToOneField(
        model_name="models.TUser",
        to_field="id",
        related_name="short_user_info"
    )
    age = fields.IntField()

Reproducing the issue:

    print("Creating user and user info")
    user = await TUser.create(name="Test User")
    user_info = await VeryLongNameForTestingPurposesOnlyUserInfo.create(
        user_id=user.id,
        not_too_long_user_age=30,
    )
    short_info = await ShortUserInfo.create(
        user_id=user.id,
        age=30,
    )

    print("Working")
    user = await TUser.filter(name="Test User").select_related("short_user_info").first()
    user_info = user.short_user_info
    user_info.age = 31
    await user_info.save()
    
    print("Not Working")
    user = await TUser.filter(name="Test User").select_related("user_information").first()
    user_info = user.user_information
    user_info.not_too_long_user_age = 32
    await user_info.save(
        # update_fields=["not_too_long_user_age"]
    )

This will raise:

IncompleteInstanceError: VeryLongNameForTestingPurposesOnlyUserInfo is a partial model, can only be saved with the relevant update_field provided

(Saving with update_fields works.)

Expected behavior
Saving with select_related should work regardless of the model name length.

[waketzheng]

Can't reproduce with the following code:

from __future__ import annotations

from tortoise import Model, fields, run_async
from tortoise.contrib.test import init_memory_sqlite


class TUser(Model):
    id = fields.UUIDField(primary_key=True)
    name = fields.CharField(max_length=100)

    # For o2o relation, use BackwardOneToOneRelation or ModelClass instead of ReverseRelation
    user_information: VeryLongNameForTestingPurposesOnlyUserInfo
    short_user_info: fields.BackwardOneToOneRelation[ShortUserInfo]


class VeryLongNameForTestingPurposesOnlyUserInfo(Model):
    id = fields.UUIDField(primary_key=True)
    user: fields.OneToOneNullableRelation[TUser] = fields.OneToOneField(
        model_name="models.TUser", to_field="id", related_name="user_information"
    )
    not_too_long_user_age = fields.IntField()

    def __repr__(self) -> str:
        return f"{self.__class__.__name__}(id={self.id}, not_too_long_user_age={self.not_too_long_user_age})"


class ShortUserInfo(Model):
    id = fields.UUIDField(primary_key=True)
    user: fields.OneToOneNullableRelation[TUser] = fields.OneToOneField(
        model_name="models.TUser", to_field="id", related_name="short_user_info"
    )
    age = fields.IntField()


@init_memory_sqlite
async def main():
    print("Creating user and user info")
    user = await TUser.create(name="Test User")
    user_info = await VeryLongNameForTestingPurposesOnlyUserInfo.create(
        user_id=user.id,
        not_too_long_user_age=30,
    )
    short_info = await ShortUserInfo.create(user_id=user.id, age=30)
    print(f"{short_info = }")

    print("Working")
    user = await TUser.filter(name="Test User").select_related("short_user_info").first()
    assert user
    user_short_info = user.short_user_info
    user_short_info.age = 31
    await user_short_info.save()

    print("Not Working")
    user = await TUser.filter(name="Test User").select_related("user_information").first()
    assert user
    user_info = user.user_information
    user_info.not_too_long_user_age = 32
    await user_info.save(
        # update_fields=["not_too_long_user_age"]
    )
    print(f"{await user_info.filter(id=user_info.id).first() = }")


if __name__ == "__main__":
    run_async(main())

[rgabor-dev]

Hey @waketzheng, thanks for looking at it. It is happening when using a Postgres database. Probably because of the 64 char hard limit: https://www.postgresql.org/docs/current/runtime-config-preset.html#GUC-MAX-IDENTIFIER-LENGTH