Upgrade to Pydantic 2

Change imports
Undefined => PydanticUndefined
Update SQLModelMetaclass and SQLModel __init__ and __new__ functions
Update SQL Alchemy type inference

docs/tutorial/fastapi/multiple-models.md

@@ -174,13 +174,13 @@ Now we use the type annotation `HeroCreate` for the request JSON data in the `he
 # Code below omitted 👇
 ```
 
-Then we create a new `Hero` (this is the actual **table** model that saves things to the database) using `Hero.from_orm()`.
+Then we create a new `Hero` (this is the actual **table** model that saves things to the database) using `Hero.model_validate()`.
 
-The method `.from_orm()` reads data from another object with attributes and creates a new instance of this class, in this case `Hero`.
+The method `.model_validate()` reads data from another object with attributes and creates a new instance of this class, in this case `Hero`.
 
 The alternative is `Hero.parse_obj()` that reads data from a dictionary.
 
-But as in this case, we have a `HeroCreate` instance in the `hero` variable. This is an object with attributes, so we use `.from_orm()` to read those attributes.
+But as in this case, we have a `HeroCreate` instance in the `hero` variable. This is an object with attributes, so we use `.model_validate()` to read those attributes.
 
 With this, we create a new `Hero` instance (the one for the database) and put it in the variable `db_hero` from the data in the `hero` variable that is the `HeroCreate` instance we received from the request.
 

docs_src/tutorial/fastapi/app_testing/tutorial001/main.py

@@ -54,7 +54,7 @@ def on_startup():
 
 @app.post("/heroes/", response_model=HeroRead)
 def create_hero(*, session: Session = Depends(get_session), hero: HeroCreate):
-    db_hero = Hero.from_orm(hero)
+    db_hero = Hero.model_validate(hero)
     session.add(db_hero)
     session.commit()
     session.refresh(db_hero)

docs_src/tutorial/fastapi/delete/tutorial001.py

@@ -50,7 +50,7 @@ def on_startup():
 @app.post("/heroes/", response_model=HeroRead)
 def create_hero(hero: HeroCreate):
     with Session(engine) as session:
-        db_hero = Hero.from_orm(hero)
+        db_hero = Hero.model_validate(hero)
         session.add(db_hero)
         session.commit()
         session.refresh(db_hero)

docs_src/tutorial/fastapi/limit_and_offset/tutorial001.py

@@ -44,7 +44,7 @@ def on_startup():
 @app.post("/heroes/", response_model=HeroRead)
 def create_hero(hero: HeroCreate):
     with Session(engine) as session:
-        db_hero = Hero.from_orm(hero)
+        db_hero = Hero.model_validate(hero)
         session.add(db_hero)
         session.commit()
         session.refresh(db_hero)

docs_src/tutorial/fastapi/multiple_models/tutorial001.py

@@ -46,7 +46,7 @@ def on_startup():
 @app.post("/heroes/", response_model=HeroRead)
 def create_hero(hero: HeroCreate):
     with Session(engine) as session:
-        db_hero = Hero.from_orm(hero)
+        db_hero = Hero.model_validate(hero)
         session.add(db_hero)
         session.commit()
         session.refresh(db_hero)

docs_src/tutorial/fastapi/multiple_models/tutorial002.py

@@ -44,7 +44,7 @@ def on_startup():
 @app.post("/heroes/", response_model=HeroRead)
 def create_hero(hero: HeroCreate):
     with Session(engine) as session:
-        db_hero = Hero.from_orm(hero)
+        db_hero = Hero.model_validate(hero)
         session.add(db_hero)
         session.commit()
         session.refresh(db_hero)

docs_src/tutorial/fastapi/read_one/tutorial001.py

@@ -44,7 +44,7 @@ def on_startup():
 @app.post("/heroes/", response_model=HeroRead)
 def create_hero(hero: HeroCreate):
     with Session(engine) as session:
-        db_hero = Hero.from_orm(hero)
+        db_hero = Hero.model_validate(hero)
         session.add(db_hero)
         session.commit()
         session.refresh(db_hero)

docs_src/tutorial/fastapi/relationships/tutorial001.py

@@ -92,7 +92,7 @@ def on_startup():
 
 @app.post("/heroes/", response_model=HeroRead)
 def create_hero(*, session: Session = Depends(get_session), hero: HeroCreate):
-    db_hero = Hero.from_orm(hero)
+    db_hero = Hero.model_validate(hero)
     session.add(db_hero)
     session.commit()
     session.refresh(db_hero)
@@ -147,7 +147,7 @@ def delete_hero(*, session: Session = Depends(get_session), hero_id: int):
 
 @app.post("/teams/", response_model=TeamRead)
 def create_team(*, session: Session = Depends(get_session), team: TeamCreate):
-    db_team = Team.from_orm(team)
+    db_team = Team.model_validate(team)
     session.add(db_team)
     session.commit()
     session.refresh(db_team)

docs_src/tutorial/fastapi/session_with_dependency/tutorial001.py

@@ -54,7 +54,7 @@ def on_startup():
 
 @app.post("/heroes/", response_model=HeroRead)
 def create_hero(*, session: Session = Depends(get_session), hero: HeroCreate):
-    db_hero = Hero.from_orm(hero)
+    db_hero = Hero.model_validate(hero)
     session.add(db_hero)
     session.commit()
     session.refresh(db_hero)

docs_src/tutorial/fastapi/teams/tutorial001.py

@@ -83,7 +83,7 @@ def on_startup():
 
 @app.post("/heroes/", response_model=HeroRead)
 def create_hero(*, session: Session = Depends(get_session), hero: HeroCreate):
-    db_hero = Hero.from_orm(hero)
+    db_hero = Hero.model_validate(hero)
     session.add(db_hero)
     session.commit()
     session.refresh(db_hero)
@@ -138,7 +138,7 @@ def delete_hero(*, session: Session = Depends(get_session), hero_id: int):
 
 @app.post("/teams/", response_model=TeamRead)
 def create_team(*, session: Session = Depends(get_session), team: TeamCreate):
-    db_team = Team.from_orm(team)
+    db_team = Team.model_validate(team)
     session.add(db_team)
     session.commit()
     session.refresh(db_team)

docs_src/tutorial/fastapi/update/tutorial001.py

@@ -50,7 +50,7 @@ def on_startup():
 @app.post("/heroes/", response_model=HeroRead)
 def create_hero(hero: HeroCreate):
     with Session(engine) as session:
-        db_hero = Hero.from_orm(hero)
+        db_hero = Hero.model_validate(hero)
         session.add(db_hero)
         session.commit()
         session.refresh(db_hero)

pyproject.toml

@@ -33,7 +33,7 @@ classifiers = [
 [tool.poetry.dependencies]
 python = "^3.7"
 SQLAlchemy = ">=2.0.0,<=2.0.11"
-pydantic = "^1.8.2"
+pydantic = "^2.1.1"
 
 [tool.poetry.dev-dependencies]
 pytest = "^7.0.1"
@@ -46,12 +46,13 @@ pillow = "^9.3.0"
 cairosvg = "^2.5.2"
 mdx-include = "^1.4.1"
 coverage = {extras = ["toml"], version = "^6.2"}
-fastapi = "^0.68.1"
+fastapi = "^0.100.0"
 requests = "^2.26.0"
 autoflake = "^1.4"
 isort = "^5.9.3"
 async_generator = {version = "*", python = "~3.7"}
 async-exit-stack = {version = "*", python = "~3.7"}
+httpx = "^0.24.1"
 
 [build-system]
 requires = ["poetry-core"]

sqlmodel/main.py

@@ -19,19 +19,17 @@ from typing import (
     Set,
     Tuple,
     Type,
-    TypeVar,
+    TypeVar,ForwardRef,
     Union,
-    cast,
+    cast,get_origin,get_args
 )
 
-from pydantic import BaseConfig, BaseModel
-from pydantic.errors import ConfigError, DictError
-from pydantic.fields import SHAPE_SINGLETON
+from pydantic import BaseModel, ValidationError
+from pydantic_core import PydanticUndefined, PydanticUndefinedType
 from pydantic.fields import FieldInfo as PydanticFieldInfo
-from pydantic.fields import ModelField, Undefined, UndefinedType
-from pydantic.main import ModelMetaclass, validate_model
-from pydantic.typing import NoArgAnyCallable, resolve_annotations
-from pydantic.utils import ROOT_KEY, Representation
+from pydantic._internal._model_construction import ModelMetaclass
+from pydantic._internal._repr import Representation
+from pydantic._internal._fields import PydanticGeneralMetadata
 from sqlalchemy import Boolean, Column, Date, DateTime
 from sqlalchemy import Enum as sa_Enum
 from sqlalchemy import Float, ForeignKey, Integer, Interval, Numeric, inspect
@@ -43,8 +41,10 @@ from sqlalchemy.sql.schema import MetaData
 from sqlalchemy.sql.sqltypes import LargeBinary, Time
 
 from .sql.sqltypes import GUID, AutoString
+from .typing import SQLModelConfig
 
 _T = TypeVar("_T")
+NoArgAnyCallable = Callable[[], Any]
 
 
 def __dataclass_transform__(
@@ -58,22 +58,22 @@ def __dataclass_transform__(
 
 
 class FieldInfo(PydanticFieldInfo):
-    def __init__(self, default: Any = Undefined, **kwargs: Any) -> None:
+    def __init__(self, default: Any = PydanticUndefined, **kwargs: Any) -> None:
         primary_key = kwargs.pop("primary_key", False)
-        nullable = kwargs.pop("nullable", Undefined)
-        foreign_key = kwargs.pop("foreign_key", Undefined)
+        nullable = kwargs.pop("nullable", PydanticUndefined)
+        foreign_key = kwargs.pop("foreign_key", PydanticUndefined)
         unique = kwargs.pop("unique", False)
-        index = kwargs.pop("index", Undefined)
-        sa_column = kwargs.pop("sa_column", Undefined)
-        sa_column_args = kwargs.pop("sa_column_args", Undefined)
-        sa_column_kwargs = kwargs.pop("sa_column_kwargs", Undefined)
-        if sa_column is not Undefined:
-            if sa_column_args is not Undefined:
+        index = kwargs.pop("index", PydanticUndefined)
+        sa_column = kwargs.pop("sa_column", PydanticUndefined)
+        sa_column_args = kwargs.pop("sa_column_args", PydanticUndefined)
+        sa_column_kwargs = kwargs.pop("sa_column_kwargs", PydanticUndefined)
+        if sa_column is not PydanticUndefined:
+            if sa_column_args is not PydanticUndefined:
                 raise RuntimeError(
                     "Passing sa_column_args is not supported when "
                     "also passing a sa_column"
                 )
-            if sa_column_kwargs is not Undefined:
+            if sa_column_kwargs is not PydanticUndefined:
                 raise RuntimeError(
                     "Passing sa_column_kwargs is not supported when "
                     "also passing a sa_column"
@@ -118,7 +118,7 @@ class RelationshipInfo(Representation):
 
 
 def Field(
-    default: Any = Undefined,
+    default: Any = PydanticUndefined,
     *,
     default_factory: Optional[NoArgAnyCallable] = None,
     alias: Optional[str] = None,
@@ -145,11 +145,11 @@ def Field(
     primary_key: bool = False,
     foreign_key: Optional[Any] = None,
     unique: bool = False,
-    nullable: Union[bool, UndefinedType] = Undefined,
-    index: Union[bool, UndefinedType] = Undefined,
-    sa_column: Union[Column, UndefinedType] = Undefined,  # type: ignore
-    sa_column_args: Union[Sequence[Any], UndefinedType] = Undefined,
-    sa_column_kwargs: Union[Mapping[str, Any], UndefinedType] = Undefined,
+    nullable: Union[bool, PydanticUndefinedType] = PydanticUndefined,
+    index: Union[bool, PydanticUndefinedType] = PydanticUndefined,
+    sa_column: Union[Column, PydanticUndefinedType] = PydanticUndefined,  # type: ignore
+    sa_column_args: Union[Sequence[Any], PydanticUndefinedType] = PydanticUndefined,
+    sa_column_kwargs: Union[Mapping[str, Any], PydanticUndefinedType] = PydanticUndefined,
     schema_extra: Optional[Dict[str, Any]] = None,
 ) -> Any:
     current_schema_extra = schema_extra or {}
@@ -183,7 +183,6 @@ def Field(
         sa_column_kwargs=sa_column_kwargs,
         **current_schema_extra,
     )
-    field_info._validate()
     return field_info
 
 
@@ -191,7 +190,7 @@ def Relationship(
     *,
     back_populates: Optional[str] = None,
     link_model: Optional[Any] = None,
-    sa_relationship: Optional[RelationshipProperty] = None,  # type: ignore
+    sa_relationship: Optional[RelationshipProperty] = None,
     sa_relationship_args: Optional[Sequence[Any]] = None,
     sa_relationship_kwargs: Optional[Mapping[str, Any]] = None,
 ) -> Any:
@@ -208,18 +207,18 @@ def Relationship(
 @__dataclass_transform__(kw_only_default=True, field_descriptors=(Field, FieldInfo))
 class SQLModelMetaclass(ModelMetaclass, DeclarativeMeta):
     __sqlmodel_relationships__: Dict[str, RelationshipInfo]
-    __config__: Type[BaseConfig]
-    __fields__: Dict[str, ModelField]
+    model_config: Type[SQLModelConfig]
+    model_fields: Dict[str, FieldInfo]
 
     # Replicate SQLAlchemy
     def __setattr__(cls, name: str, value: Any) -> None:
-        if getattr(cls.__config__, "table", False):
+        if cls.model_config.get("table", False):
             DeclarativeMeta.__setattr__(cls, name, value)
         else:
             super().__setattr__(name, value)
 
     def __delattr__(cls, name: str) -> None:
-        if getattr(cls.__config__, "table", False):
+        if cls.model_config.get("table", False):
             DeclarativeMeta.__delattr__(cls, name)
         else:
             super().__delattr__(name)
@@ -232,11 +231,10 @@ class SQLModelMetaclass(ModelMetaclass, DeclarativeMeta):
         class_dict: Dict[str, Any],
         **kwargs: Any,
     ) -> Any:
+        
         relationships: Dict[str, RelationshipInfo] = {}
         dict_for_pydantic = {}
-        original_annotations = resolve_annotations(
-            class_dict.get("__annotations__", {}), class_dict.get("__module__", None)
-        )
+        original_annotations = class_dict.get("__annotations__", {})
         pydantic_annotations = {}
         relationship_annotations = {}
         for k, v in class_dict.items():
@@ -260,7 +258,7 @@ class SQLModelMetaclass(ModelMetaclass, DeclarativeMeta):
         # superclass causing an error
         allowed_config_kwargs: Set[str] = {
             key
-            for key in dir(BaseConfig)
+            for key in dir(SQLModelConfig)
             if not (
                 key.startswith("__") and key.endswith("__")
             )  # skip dunder methods and attributes
@@ -270,41 +268,49 @@ class SQLModelMetaclass(ModelMetaclass, DeclarativeMeta):
             key: pydantic_kwargs.pop(key)
             for key in pydantic_kwargs.keys() & allowed_config_kwargs
         }
+        config_table = getattr(class_dict.get('Config', object()), 'table', False)
+        # If we have a table, we need to have defaults for all fields
+        # Pydantic v2 sets a __pydantic_core_schema__ which is very hard to change. Changing the fields does not do anything
+        if config_table is True:
+            for key in original_annotations.keys():
+                if dict_used.get(key, PydanticUndefined) is PydanticUndefined:
+                    dict_used[key] = None
+        
         new_cls = super().__new__(cls, name, bases, dict_used, **config_kwargs)
         new_cls.__annotations__ = {
             **relationship_annotations,
             **pydantic_annotations,
             **new_cls.__annotations__,
         }
-
+        
         def get_config(name: str) -> Any:
-            config_class_value = getattr(new_cls.__config__, name, Undefined)
-            if config_class_value is not Undefined:
+            config_class_value = new_cls.model_config.get(name, PydanticUndefined)
+            if config_class_value is not PydanticUndefined:
                 return config_class_value
-            kwarg_value = kwargs.get(name, Undefined)
-            if kwarg_value is not Undefined:
+            kwarg_value = kwargs.get(name, PydanticUndefined)
+            if kwarg_value is not PydanticUndefined:
                 return kwarg_value
-            return Undefined
+            return PydanticUndefined
 
         config_table = get_config("table")
         if config_table is True:
             # If it was passed by kwargs, ensure it's also set in config
-            new_cls.__config__.table = config_table
-            for k, v in new_cls.__fields__.items():
+            new_cls.model_config['table'] = config_table
+            for k, v in new_cls.model_fields.items():
                 col = get_column_from_field(v)
                 setattr(new_cls, k, col)
             # Set a config flag to tell FastAPI that this should be read with a field
             # in orm_mode instead of preemptively converting it to a dict.
-            # This could be done by reading new_cls.__config__.table in FastAPI, but
+            # This could be done by reading new_cls.model_config['table'] in FastAPI, but
             # that's very specific about SQLModel, so let's have another config that
             # other future tools based on Pydantic can use.
-            new_cls.__config__.read_with_orm_mode = True
+            new_cls.model_config['read_from_attributes'] = True
 
         config_registry = get_config("registry")
-        if config_registry is not Undefined:
+        if config_registry is not PydanticUndefined:
             config_registry = cast(registry, config_registry)
             # If it was passed by kwargs, ensure it's also set in config
-            new_cls.__config__.registry = config_table
+            new_cls.model_config['registry'] = config_table
             setattr(new_cls, "_sa_registry", config_registry)
             setattr(new_cls, "metadata", config_registry.metadata)
             setattr(new_cls, "__abstract__", True)
@@ -320,13 +326,13 @@ class SQLModelMetaclass(ModelMetaclass, DeclarativeMeta):
         # triggers an error
         base_is_table = False
         for base in bases:
-            config = getattr(base, "__config__")
+            config = getattr(base, "model_config")
             if config and getattr(config, "table", False):
                 base_is_table = True
                 break
-        if getattr(cls.__config__, "table", False) and not base_is_table:
+        if cls.model_config.get("table", False) and not base_is_table:
             dict_used = dict_.copy()
-            for field_name, field_value in cls.__fields__.items():
+            for field_name, field_value in cls.model_fields.items():
                 dict_used[field_name] = get_column_from_field(field_value)
             for rel_name, rel_info in cls.__sqlmodel_relationships__.items():
                 if rel_info.sa_relationship:
@@ -335,16 +341,15 @@ class SQLModelMetaclass(ModelMetaclass, DeclarativeMeta):
                     dict_used[rel_name] = rel_info.sa_relationship
                     continue
                 ann = cls.__annotations__[rel_name]
-                temp_field = ModelField.infer(
-                    name=rel_name,
-                    value=rel_info,
-                    annotation=ann,
-                    class_validators=None,
-                    config=BaseConfig,
-                )
-                relationship_to = temp_field.type_
-                if isinstance(temp_field.type_, ForwardRef):
-                    relationship_to = temp_field.type_.__forward_arg__
+                relationship_to = get_origin(ann)
+                # If Union (Optional), get the real field
+                if relationship_to is Union:
+                    relationship_to = get_args(ann)[0]
+                # If a list, then also get the real field
+                elif relationship_to is list:
+                    relationship_to = get_args(ann)[0]
+                if isinstance(relationship_to, ForwardRef):
+                    relationship_to = relationship_to.__forward_arg__
                 rel_kwargs: Dict[str, Any] = {}
                 if rel_info.back_populates:
                     rel_kwargs["back_populates"] = rel_info.back_populates
@@ -362,7 +367,7 @@ class SQLModelMetaclass(ModelMetaclass, DeclarativeMeta):
                     rel_args.extend(rel_info.sa_relationship_args)
                 if rel_info.sa_relationship_kwargs:
                     rel_kwargs.update(rel_info.sa_relationship_kwargs)
-                rel_value: RelationshipProperty = relationship(  # type: ignore
+                rel_value: RelationshipProperty = relationship( 
                     relationship_to, *rel_args, **rel_kwargs
                 )
                 dict_used[rel_name] = rel_value
@@ -372,68 +377,78 @@ class SQLModelMetaclass(ModelMetaclass, DeclarativeMeta):
             ModelMetaclass.__init__(cls, classname, bases, dict_, **kw)
 
 
-def get_sqlalchemy_type(field: ModelField) -> Any:
-    if issubclass(field.type_, str):
-        if field.field_info.max_length:
-            return AutoString(length=field.field_info.max_length)
+def get_sqlalchemy_type(field: FieldInfo) -> Any:
+    type_ = field.annotation
+    # Resolve Optional fields
+    if type_ is not None and get_origin(type_) is Union:
+        bases = get_args(type_)
+        if len(bases) > 2:
+            raise RuntimeError("Cannot have a (non-optional) union as a SQL alchemy field")
+        type_ = bases[0]     
+
+    # The 3rd is PydanticGeneralMetadata
+    metadata = _get_field_metadata(field)
+    if issubclass(type_, str):
+        if getattr(metadata, "max_length", None):
+            return AutoString(length=metadata.max_length)
         return AutoString
-    if issubclass(field.type_, float):
+    if issubclass(type_, float):
         return Float
-    if issubclass(field.type_, bool):
+    if issubclass(type_, bool):
         return Boolean
-    if issubclass(field.type_, int):
+    if issubclass(type_, int):
         return Integer
-    if issubclass(field.type_, datetime):
+    if issubclass(type_, datetime):
         return DateTime
-    if issubclass(field.type_, date):
+    if issubclass(type_, date):
         return Date
-    if issubclass(field.type_, timedelta):
+    if issubclass(type_, timedelta):
         return Interval
-    if issubclass(field.type_, time):
+    if issubclass(type_, time):
         return Time
-    if issubclass(field.type_, Enum):
-        return sa_Enum(field.type_)
-    if issubclass(field.type_, bytes):
+    if issubclass(type_, Enum):
+        return sa_Enum(type_)
+    if issubclass(type_, bytes):
         return LargeBinary
-    if issubclass(field.type_, Decimal):
+    if issubclass(type_, Decimal):
         return Numeric(
-            precision=getattr(field.type_, "max_digits", None),
-            scale=getattr(field.type_, "decimal_places", None),
+            precision=getattr(metadata, "max_digits", None),
+            scale=getattr(metadata, "decimal_places", None),
         )
-    if issubclass(field.type_, ipaddress.IPv4Address):
+    if issubclass(type_, ipaddress.IPv4Address):
         return AutoString
-    if issubclass(field.type_, ipaddress.IPv4Network):
+    if issubclass(type_, ipaddress.IPv4Network):
         return AutoString
-    if issubclass(field.type_, ipaddress.IPv6Address):
+    if issubclass(type_, ipaddress.IPv6Address):
         return AutoString
-    if issubclass(field.type_, ipaddress.IPv6Network):
+    if issubclass(type_, ipaddress.IPv6Network):
         return AutoString
-    if issubclass(field.type_, Path):
+    if issubclass(type_, Path):
         return AutoString
-    if issubclass(field.type_, uuid.UUID):
+    if issubclass(type_, uuid.UUID):
         return GUID
-    raise ValueError(f"The field {field.name} has no matching SQLAlchemy type")
+    raise ValueError(f"The field {field.title} has no matching SQLAlchemy type")
 
 
-def get_column_from_field(field: ModelField) -> Column:  # type: ignore
-    sa_column = getattr(field.field_info, "sa_column", Undefined)
+def get_column_from_field(field: FieldInfo) -> Column:  # type: ignore
+    sa_column = getattr(field, "sa_column", PydanticUndefined)
     if isinstance(sa_column, Column):
         return sa_column
     sa_type = get_sqlalchemy_type(field)
-    primary_key = getattr(field.field_info, "primary_key", False)
-    index = getattr(field.field_info, "index", Undefined)
-    if index is Undefined:
+    primary_key = getattr(field, "primary_key", False)
+    index = getattr(field, "index", PydanticUndefined)
+    if index is PydanticUndefined:
         index = False
     nullable = not primary_key and _is_field_noneable(field)
     # Override derived nullability if the nullable property is set explicitly
     # on the field
-    if hasattr(field.field_info, "nullable"):
-        field_nullable = getattr(field.field_info, "nullable")
-        if field_nullable != Undefined:
+    if hasattr(field, "nullable"):
+        field_nullable = getattr(field, "nullable")
+        if field_nullable != PydanticUndefined:
             nullable = field_nullable
     args = []
-    foreign_key = getattr(field.field_info, "foreign_key", None)
-    unique = getattr(field.field_info, "unique", False)
+    foreign_key = getattr(field, "foreign_key", None)
+    unique = getattr(field, "unique", False)
     if foreign_key:
         args.append(ForeignKey(foreign_key))
     kwargs = {
@@ -442,18 +457,18 @@ def get_column_from_field(field: ModelField) -> Column:  # type: ignore
         "index": index,
         "unique": unique,
     }
-    sa_default = Undefined
-    if field.field_info.default_factory:
-        sa_default = field.field_info.default_factory
-    elif field.field_info.default is not Undefined:
-        sa_default = field.field_info.default
-    if sa_default is not Undefined:
+    sa_default = PydanticUndefined
+    if field.default_factory:
+        sa_default = field.default_factory
+    elif field.default is not PydanticUndefined:
+        sa_default = field.default
+    if sa_default is not PydanticUndefined:
         kwargs["default"] = sa_default
-    sa_column_args = getattr(field.field_info, "sa_column_args", Undefined)
-    if sa_column_args is not Undefined:
+    sa_column_args = getattr(field, "sa_column_args", PydanticUndefined)
+    if sa_column_args is not PydanticUndefined:
         args.extend(list(cast(Sequence[Any], sa_column_args)))
-    sa_column_kwargs = getattr(field.field_info, "sa_column_kwargs", Undefined)
-    if sa_column_kwargs is not Undefined:
+    sa_column_kwargs = getattr(field, "sa_column_kwargs", PydanticUndefined)
+    if sa_column_kwargs is not PydanticUndefined:
         kwargs.update(cast(Dict[Any, Any], sa_column_kwargs))
     return Column(sa_type, *args, **kwargs)  # type: ignore
 
@@ -462,13 +477,6 @@ class_registry = weakref.WeakValueDictionary()  # type: ignore
 
 default_registry = registry()
 
-
-def _value_items_is_true(v: Any) -> bool:
-    # Re-implement Pydantic's ValueItems.is_true() as it hasn't been released as of
-    # the current latest, Pydantic 1.8.2
-    return v is True or v is ...
-
-
 _TSQLModel = TypeVar("_TSQLModel", bound="SQLModel")
 
 
@@ -476,43 +484,17 @@ class SQLModel(BaseModel, metaclass=SQLModelMetaclass, registry=default_registry
     # SQLAlchemy needs to set weakref(s), Pydantic will set the other slots values
     __slots__ = ("__weakref__",)
     __tablename__: ClassVar[Union[str, Callable[..., str]]]
-    __sqlmodel_relationships__: ClassVar[Dict[str, RelationshipProperty]]  # type: ignore
+    __sqlmodel_relationships__: ClassVar[Dict[str, RelationshipProperty]]
     __name__: ClassVar[str]
     metadata: ClassVar[MetaData]
     __allow_unmapped__ = True  # https://docs.sqlalchemy.org/en/20/changelog/migration_20.html#migration-20-step-six
-
-    class Config:
-        orm_mode = True
-
-    def __new__(cls, *args: Any, **kwargs: Any) -> Any:
-        new_object = super().__new__(cls)
-        # SQLAlchemy doesn't call __init__ on the base class
-        # Ref: https://docs.sqlalchemy.org/en/14/orm/constructors.html
-        # Set __fields_set__ here, that would have been set when calling __init__
-        # 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, "__fields_set__", set())
-        return new_object
+    model_config = SQLModelConfig(from_attributes=True)
 
     def __init__(__pydantic_self__, **data: Any) -> None:
-        # Uses something other than `self` the first arg to allow "self" as a
-        # settable attribute
-        values, fields_set, validation_error = validate_model(
-            __pydantic_self__.__class__, data
-        )
-        # Only raise errors if not a SQLModel model
-        if (
-            not getattr(__pydantic_self__.__config__, "table", False)
-            and validation_error
-        ):
-            raise validation_error
-        # Do not set values as in Pydantic, pass them through setattr, so SQLAlchemy
-        # can handle them
-        # object.__setattr__(__pydantic_self__, '__dict__', values)
-        for key, value in values.items():
-            setattr(__pydantic_self__, key, value)
-        object.__setattr__(__pydantic_self__, "__fields_set__", fields_set)
-        non_pydantic_keys = data.keys() - values.keys()
+        old_dict = __pydantic_self__.__dict__.copy()
+        super().__init__(**data)
+        __pydantic_self__.__dict__ = old_dict | __pydantic_self__.__dict__
+        non_pydantic_keys = data.keys() - __pydantic_self__.model_fields
         for key in non_pydantic_keys:
             if key in __pydantic_self__.__sqlmodel_relationships__:
                 setattr(__pydantic_self__, key, data[key])
@@ -523,135 +505,36 @@ class SQLModel(BaseModel, metaclass=SQLModelMetaclass, registry=default_registry
             return
         else:
             # Set in SQLAlchemy, before Pydantic to trigger events and updates
-            if getattr(self.__config__, "table", False) and is_instrumented(self, name):  # type: ignore
+            if self.model_config.get("table", False) and is_instrumented(self, name):
                 set_attribute(self, name, value)
             # Set in Pydantic model to trigger possible validation changes, only for
             # non relationship values
             if name not in self.__sqlmodel_relationships__:
-                super().__setattr__(name, value)
-
-    @classmethod
-    def from_orm(
-        cls: Type[_TSQLModel], obj: Any, update: Optional[Dict[str, Any]] = None
-    ) -> _TSQLModel:
-        # Duplicated from Pydantic
-        if not cls.__config__.orm_mode:
-            raise ConfigError(
-                "You must have the config attribute orm_mode=True to use from_orm"
-            )
-        obj = {ROOT_KEY: obj} if cls.__custom_root_type__ else cls._decompose_class(obj)
-        # SQLModel, support update dict
-        if update is not None:
-            obj = {**obj, **update}
-        # End SQLModel support dict
-        if not getattr(cls.__config__, "table", False):
-            # If not table, normal Pydantic code
-            m: _TSQLModel = cls.__new__(cls)
-        else:
-            # If table, create the new instance normally to make SQLAlchemy create
-            # the _sa_instance_state attribute
-            m = cls()
-        values, fields_set, validation_error = validate_model(cls, obj)
-        if validation_error:
-            raise validation_error
-        # Updated to trigger SQLAlchemy internal handling
-        if not getattr(cls.__config__, "table", False):
-            object.__setattr__(m, "__dict__", values)
-        else:
-            for key, value in values.items():
-                setattr(m, key, value)
-        # Continue with standard Pydantic logic
-        object.__setattr__(m, "__fields_set__", fields_set)
-        m._init_private_attributes()
-        return m
-
-    @classmethod
-    def parse_obj(
-        cls: Type[_TSQLModel], obj: Any, update: Optional[Dict[str, Any]] = None
-    ) -> _TSQLModel:
-        obj = cls._enforce_dict_if_root(obj)
-        # SQLModel, support update dict
-        if update is not None:
-            obj = {**obj, **update}
-        # End SQLModel support dict
-        return super().parse_obj(obj)
+                super(SQLModel, self).__setattr__(name, value)
 
     def __repr_args__(self) -> Sequence[Tuple[Optional[str], Any]]:
         # Don't show SQLAlchemy private attributes
         return [(k, v) for k, v in self.__dict__.items() if not k.startswith("_sa_")]
 
-    # From Pydantic, override to enforce validation with dict
-    @classmethod
-    def validate(cls: Type[_TSQLModel], value: Any) -> _TSQLModel:
-        if isinstance(value, cls):
-            return value.copy() if cls.__config__.copy_on_model_validation else value
-
-        value = cls._enforce_dict_if_root(value)
-        if isinstance(value, dict):
-            values, fields_set, validation_error = validate_model(cls, value)
-            if validation_error:
-                raise validation_error
-            model = cls(**value)
-            # Reset fields set, this would have been done in Pydantic in __init__
-            object.__setattr__(model, "__fields_set__", fields_set)
-            return model
-        elif cls.__config__.orm_mode:
-            return cls.from_orm(value)
-        elif cls.__custom_root_type__:
-            return cls.parse_obj(value)
-        else:
-            try:
-                value_as_dict = dict(value)
-            except (TypeError, ValueError) as e:
-                raise DictError() from e
-            return cls(**value_as_dict)
-
-    # From Pydantic, override to only show keys from fields, omit SQLAlchemy attributes
-    def _calculate_keys(
-        self,
-        include: Optional[Mapping[Union[int, str], Any]],
-        exclude: Optional[Mapping[Union[int, str], Any]],
-        exclude_unset: bool,
-        update: Optional[Dict[str, Any]] = None,
-    ) -> Optional[AbstractSet[str]]:
-        if include is None and exclude is None and not exclude_unset:
-            # Original in Pydantic:
-            # return None
-            # Updated to not return SQLAlchemy attributes
-            # Do not include relationships as that would easily lead to infinite
-            # recursion, or traversing the whole database
-            return self.__fields__.keys()  # | self.__sqlmodel_relationships__.keys()
-
-        keys: AbstractSet[str]
-        if exclude_unset:
-            keys = self.__fields_set__.copy()
-        else:
-            # Original in Pydantic:
-            # keys = self.__dict__.keys()
-            # Updated to not return SQLAlchemy attributes
-            # Do not include relationships as that would easily lead to infinite
-            # recursion, or traversing the whole database
-            keys = self.__fields__.keys()  # | self.__sqlmodel_relationships__.keys()
-        if include is not None:
-            keys &= include.keys()
-
-        if update:
-            keys -= update.keys()
-
-        if exclude:
-            keys -= {k for k, v in exclude.items() if _value_items_is_true(v)}
-
-        return keys
 
     @declared_attr  # type: ignore
     def __tablename__(cls) -> str:
         return cls.__name__.lower()
 
 
-def _is_field_noneable(field: ModelField) -> bool:
-    if not field.required:
-        # Taken from [Pydantic](https://github.com/samuelcolvin/pydantic/blob/v1.8.2/pydantic/fields.py#L946-L947)
-        return field.allow_none and (
-            field.shape != SHAPE_SINGLETON or not field.sub_fields
-        )
+def _is_field_noneable(field: FieldInfo) -> bool:
+    if not field.is_required():
+        if field.annotation is None or field.annotation is type(None):
+            return True
+        if get_origin(field.annotation) is Union:
+            for base in get_args(field.annotation):
+                if base is type(None):
+                    return True
+        return False
     return False
+
+def _get_field_metadata(field: FieldInfo) -> object:
+    for meta in field.metadata:
+        if isinstance(meta, PydanticGeneralMetadata):
+            return meta
+    return object()

sqlmodel/typing.py

@@ -0,0 +1,7 @@
+from pydantic import ConfigDict
+from typing import Optional, Any
+
+class SQLModelConfig(ConfigDict):
+    table: Optional[bool]
+    read_from_attributes: Optional[bool]
+    registry: Optional[Any]

tests/test_instance_no_args.py

@@ -8,7 +8,7 @@ from sqlmodel import Field, SQLModel
 def test_allow_instantiation_without_arguments(clear_sqlmodel):
     class Item(SQLModel):
         id: Optional[int] = Field(default=None, primary_key=True)
-        name: str
+        name: str 
         description: Optional[str] = None
 
         class Config:

tests/test_missing_type.py

@@ -2,10 +2,11 @@ from typing import Optional
 
 import pytest
 from sqlmodel import Field, SQLModel
+from pydantic import BaseModel
 
 
 def test_missing_sql_type():
-    class CustomType:
+    class CustomType(BaseModel):
         @classmethod
         def __get_validators__(cls):
             yield cls.validate

tests/test_validation.py

@@ -1,7 +1,7 @@
 from typing import Optional
 
 import pytest
-from pydantic import validator
+from pydantic import field_validator
 from pydantic.error_wrappers import ValidationError
 from sqlmodel import SQLModel
 
@@ -22,12 +22,12 @@ def test_validation(clear_sqlmodel):
         secret_name: Optional[str] = None
         age: Optional[int] = None
 
-        @validator("name", "secret_name", "age")
+        @field_validator("name", "secret_name", "age")
         def reject_none(cls, v):
             assert v is not None
             return v
 
-    Hero.validate({"age": 25})
+    Hero.model_validate({"age": 25})
 
     with pytest.raises(ValidationError):
-        Hero.validate({"name": None, "age": 25})
+        Hero.model_validate({"name": None, "age": 25})