✨ Support sqlalchemy MappedColumn

sqlmodel/main.py

@@ -42,6 +42,7 @@
 from sqlalchemy import Enum as sa_Enum
 from sqlalchemy.orm import (
     Mapped,
+    MappedColumn,
     RelationshipProperty,
     declared_attr,
     registry,
@@ -702,13 +703,13 @@ def get_sqlalchemy_type(field: Any) -> Any:
     raise ValueError(f"{type_} has no matching SQLAlchemy type")
 
 
-def get_column_from_field(field: Any) -> Column:  # type: ignore
+def get_column_from_field(field: Any) -> Union[Column, MappedColumn]:  # type: ignore
     if IS_PYDANTIC_V2:
         field_info = field
     else:
         field_info = field.field_info
     sa_column = getattr(field_info, "sa_column", Undefined)
-    if isinstance(sa_column, Column):
+    if isinstance(sa_column, (Column, MappedColumn)):
         return sa_column
     sa_type = get_sqlalchemy_type(field)
     primary_key = getattr(field_info, "primary_key", Undefined)

tests/test_field_sa_column.py

@@ -5,7 +5,7 @@
 from sqlmodel import Field, SQLModel
 
 
-def test_sa_column_takes_precedence() -> None:
+def test_sa_column_takes_precedence(clear_sqlmodel) -> None:
     class Item(SQLModel, table=True):
         id: Optional[int] = Field(
             default=None,

tests/test_field_sa_column_mapped_column.py

@@ -0,0 +1,122 @@
+from typing import Optional
+
+import pytest
+from sqlalchemy import Integer, String
+from sqlalchemy.orm import mapped_column
+from sqlmodel import Field, SQLModel
+
+
+def test_sa_column_takes_precedence(clear_sqlmodel) -> None:
+    class Item(SQLModel, table=True):
+        id: Optional[int] = Field(
+            default=None,
+            sa_column=mapped_column(String, primary_key=True, nullable=False),
+        )
+
+    # It would have been nullable with no sa_column
+    assert Item.id.nullable is False  # type: ignore
+    assert isinstance(Item.id.type, String)  # type: ignore
+
+
+def test_sa_column_no_sa_args() -> None:
+    with pytest.raises(RuntimeError):
+
+        class Item(SQLModel, table=True):
+            id: Optional[int] = Field(
+                default=None,
+                sa_column_args=[Integer],
+                sa_column=mapped_column(Integer, primary_key=True),
+            )
+
+
+def test_sa_column_no_sa_kargs() -> None:
+    with pytest.raises(RuntimeError):
+
+        class Item(SQLModel, table=True):
+            id: Optional[int] = Field(
+                default=None,
+                sa_column_kwargs={"primary_key": True},
+                sa_column=mapped_column(Integer, primary_key=True),
+            )
+
+
+def test_sa_column_no_type() -> None:
+    with pytest.raises(RuntimeError):
+
+        class Item(SQLModel, table=True):
+            id: Optional[int] = Field(
+                default=None,
+                sa_type=Integer,
+                sa_column=mapped_column(Integer, primary_key=True),
+            )
+
+
+def test_sa_column_no_primary_key() -> None:
+    with pytest.raises(RuntimeError):
+
+        class Item(SQLModel, table=True):
+            id: Optional[int] = Field(
+                default=None,
+                primary_key=True,
+                sa_column=mapped_column(Integer, primary_key=True),
+            )
+
+
+def test_sa_column_no_nullable() -> None:
+    with pytest.raises(RuntimeError):
+
+        class Item(SQLModel, table=True):
+            id: Optional[int] = Field(
+                default=None,
+                nullable=True,
+                sa_column=mapped_column(Integer, primary_key=True),
+            )
+
+
+def test_sa_column_no_foreign_key() -> None:
+    with pytest.raises(RuntimeError):
+
+        class Team(SQLModel, table=True):
+            id: Optional[int] = Field(default=None, primary_key=True)
+            name: str
+
+        class Hero(SQLModel, table=True):
+            id: Optional[int] = Field(default=None, primary_key=True)
+            team_id: Optional[int] = Field(
+                default=None,
+                foreign_key="team.id",
+                sa_column=mapped_column(Integer, primary_key=True),
+            )
+
+
+def test_sa_column_no_unique() -> None:
+    with pytest.raises(RuntimeError):
+
+        class Item(SQLModel, table=True):
+            id: Optional[int] = Field(
+                default=None,
+                unique=True,
+                sa_column=mapped_column(Integer, primary_key=True),
+            )
+
+
+def test_sa_column_no_index() -> None:
+    with pytest.raises(RuntimeError):
+
+        class Item(SQLModel, table=True):
+            id: Optional[int] = Field(
+                default=None,
+                index=True,
+                sa_column=mapped_column(Integer, primary_key=True),
+            )
+
+
+def test_sa_column_no_ondelete() -> None:
+    with pytest.raises(RuntimeError):
+
+        class Item(SQLModel, table=True):
+            id: Optional[int] = Field(
+                default=None,
+                sa_column=mapped_column(Integer, primary_key=True),
+                ondelete="CASCADE",
+            )