refactor according to Yurii's suggestion

Author: svlandeg

sqlmodel/main.py

@@ -476,6 +476,17 @@ def Relationship(
     return relationship_info
 
 
+# Helper function to support Pydantic 2.12+ compatibility
+def _find_field_info(cls: type, field_name: str) -> Optional[FieldInfo]:
+    for c in cls.__mro__:
+        annotated = get_annotations(c.__dict__).get(field_name)  # type: ignore[arg-type]
+        if annotated:
+            for meta in getattr(annotated, "__metadata__", ()):
+                if isinstance(meta, FieldInfo):
+                    return meta
+    return None
+
+
 @__dataclass_transform__(kw_only_default=True, field_descriptors=(Field, FieldInfo))
 class SQLModelMetaclass(ModelMetaclass, DeclarativeMeta):
     __sqlmodel_relationships__: Dict[str, RelationshipInfo]
@@ -562,31 +573,17 @@ def get_config(name: str) -> Any:
             # If it was passed by kwargs, ensure it's also set in config
             set_config_value(model=new_cls, parameter="table", value=config_table)
             for k, v in get_model_fields(new_cls).items():
-                if not IS_PYDANTIC_V2:
-                    col = get_column_from_field(v)
-                    setattr(new_cls, k, col)
-                    continue
-
-                original_field = getattr(v, "_original_assignment", Undefined)
-                # Get the original sqlmodel FieldInfo, pydantic >=v2.12 changes the model
-                if isinstance(original_field, FieldInfo):
-                    field = original_field
+                if PYDANTIC_MINOR_VERSION >= (2, 12):
+                    original_field = getattr(v, "_original_assignment", Undefined)
+                    # Get the original sqlmodel FieldInfo, pydantic >=v2.12 changes the model
+                    if isinstance(original_field, FieldInfo):
+                        field = original_field
+                    else:
+                        field = _find_field_info(new_cls, field_name=k) or v  # type: ignore[assignment]
+                    field.annotation = v.annotation
+                    col = get_column_from_field(field)
                 else:
-                    field = v  # type: ignore[assignment]
-                    # Update the FieldInfo with the correct class from annotation.
-                    # This is required because pydantic overrides the field with its own
-                    # class and the reference for sqlmodel.FieldInfo is lost.
-                    for c in new_cls.__mro__:
-                        if annotated := get_annotations(c.__dict__).get(k):  # type: ignore[arg-type]
-                            for meta in getattr(annotated, "__metadata__", ()):
-                                if isinstance(meta, FieldInfo):
-                                    field = meta
-                                    break
-                            break
-
-                field.annotation = v.annotation
-                # Guarantee the field has the correct type
-                col = get_column_from_field(field)
+                    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.