commit suggestion by Yurii

Co-authored-by: Motov Yurii <109919500+YuriiMotov@users.noreply.github.com>

Author: svlandeg

sqlmodel/_compat.py

@@ -462,8 +462,8 @@ def is_field_noneable(field: "FieldInfo") -> bool:
 
     def get_sa_type_from_field(field: Any) -> Any:
         if get_origin(field.type_) is Literal:
-            return AutoString
-        elif isinstance(field.type_, type) and field.shape == SHAPE_SINGLETON:
+            return Literal
+        if isinstance(field.type_, type) and field.shape == SHAPE_SINGLETON:
             return field.type_
         raise ValueError(f"The field {field.name} has no matching SQLAlchemy type")