fix model_copy

sqlmodel/main.py

@@ -596,6 +596,10 @@ class SQLModel(BaseModel, metaclass=SQLModelMetaclass, registry=default_registry
         # in the Pydantic model so that when SQLAlchemy sets attributes that are
         # added (e.g. when querying from DB) to the __fields_set__, this already exists
         object.__setattr__(new_object, "__pydantic_fields_set__", set())
+        if not hasattr(new_object, "__pydantic_extra__"):
+            object.__setattr__(new_object, "__pydantic_extra__", None)
+        if not hasattr(new_object, "__pydantic_private__"):
+            object.__setattr__(new_object, "__pydantic_private__", None)
         return new_object
 
     def __init__(__pydantic_self__, **data: Any) -> None:

tests/test_model_copy.py

@@ -0,0 +1,49 @@
+from typing import Optional
+
+import pytest
+from pydantic import field_validator
+from pydantic.error_wrappers import ValidationError
+from sqlmodel import SQLModel, create_engine, Session, Field
+
+
+def test_model_copy(clear_sqlmodel):
+    """Test validation of implicit and explict None values.
+
+    # For consistency with pydantic, validators are not to be called on
+    # arguments that are not explicitly provided.
+
+    https://github.com/tiangolo/sqlmodel/issues/230
+    https://github.com/samuelcolvin/pydantic/issues/1223
+
+    """
+
+    class Hero(SQLModel, table=True):
+        id: Optional[int] = Field(default=None, primary_key=True)
+        name: str
+        secret_name: str
+        age: Optional[int] = None
+
+    hero = Hero(name="Deadpond", secret_name="Dive Wilson", age=25)
+
+    engine = create_engine("sqlite://")
+
+    SQLModel.metadata.create_all(engine)
+
+    with Session(engine) as session:
+        session.add(hero)
+        session.commit()
+        session.refresh(hero)
+
+    model_copy = hero.model_copy(update={"name": "Deadpond Copy"})
+
+    assert model_copy.name == "Deadpond Copy" and \
+           model_copy.secret_name == "Dive Wilson" and \
+           model_copy.age == 25
+
+    db_hero = session.get(Hero, hero.id)
+
+    db_copy = db_hero.model_copy(update={"name": "Deadpond Copy"})
+
+    assert db_copy.name == "Deadpond Copy" and \
+           db_copy.secret_name == "Dive Wilson" and \
+           db_copy.age == 25