✨ Do not allow invalid combinations of field parameters for columns and relationships, sa_column excludes sa_column_args, primary_key, nullable, etc. (#681)

* ♻️ Make sa_column exclusive, do not allow incompatible arguments, sa_column_args, primary_key, etc

* ✅ Add tests for new errors when incorrectly using sa_column

* ✅ Add tests for sa_column_args and sa_column_kwargs

* ♻️ Do not allow sa_relationship with sa_relationship_args or sa_relationship_kwargs

* ✅ Add tests for relationship errors

* ✅ Fix test for sa_column_args

tests/test_field_sa_column.py

@@ -0,0 +1,99 @@
+from typing import Optional
+
+import pytest
+from sqlalchemy import Column, Integer, String
+from sqlmodel import Field, SQLModel
+
+
+def test_sa_column_takes_precedence() -> None:
+    class Item(SQLModel, table=True):
+        id: Optional[int] = Field(
+            default=None,
+            sa_column=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=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=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=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=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=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=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=Column(Integer, primary_key=True),
+            )