🐛 Fix fields marked as "set" in models

[statt8900]

This request addresses the problem brought up in issue #87
By using the setattr to set even the default values of the SQLModel they all get added to the pydantic.BaseModel.__fields_set__ attribute regardless if the user sets them. Simply, moving the setattr for the __fields_set__ to after this iteration correctly recreates the intended behavior from pydantic. I've included the small test below that passes on my machine along with the other unit tests.

from datetime import datetime, timedelta
from sqlmodel import SQLModel, Field


def test_fields_set():
    class User(SQLModel):
        username: str
        email: str = "test@test.com"
        last_updated: datetime = Field(default_factory=datetime.now)

    user = User(username="bob")
    assert user.__fields_set__ == {"username"}
    user = User(username="bob", email="bob@test.com")
    assert user.__fields_set__ == {"username", "email"}
    user = User(
        username="bob",
        email="bob@test.com",
        last_updated=datetime.now() - timedelta(days=1),
    )
    assert user.__fields_set__ == {"username", "email", "last_updated"}

[tiangolo]

Awesome, thanks for writing thorough tests for this! 🍰 ☕

This fix will be available in SQLModel 0.0.7, released in the next hours. 🎉