Fixed the StopIteration exception raised in Sqlalchemy ModelView when the primary key is not included in the field list. (#482)

* fix #481

* fix ci

* add changelog

Author: jowilf

docs/changelog/index.md

@@ -7,6 +7,9 @@ to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
 
+* Fixed the StopIteration exception raised in Sqlalchemy ModelView when the primary key is not included in the field
+  list by [@jowilf](https://github.com/jowilf) in [#482](https://github.com/jowilf/starlette-admin/pull/482)
+
 ## [0.13.0] - 2023-01-16
 
 ### Added

starlette_admin/contrib/sqla/view.py

@@ -107,13 +107,10 @@ def __init__(
                 for f in self.model.__dict__
                 if type(self.model.__dict__[f]) is InstrumentedAttribute
             ]
-        self._setup_primary_key()
         self.fields = (converter or ModelConverter()).convert_fields_list(
             fields=self.fields, model=self.model, mapper=mapper
         )
-        self.pk_field: BaseField = next(
-            f for f in self.fields if f.name == self.pk_attr
-        )
+        self._setup_primary_key()
         self.exclude_fields_from_list = normalize_list(self.exclude_fields_from_list)  # type: ignore
         self.exclude_fields_from_detail = normalize_list(self.exclude_fields_from_detail)  # type: ignore
         self.exclude_fields_from_create = normalize_list(self.exclude_fields_from_create)  # type: ignore
@@ -157,16 +154,20 @@ def _setup_primary_key(self) -> None:
             self._pk_coerce = tuple(
                 extract_column_python_type(c) for c in self._pk_column
             )
-            pk_field = MultiplePKField(_pk_attrs)
-            self.pk_attr = pk_field.name
-            self.fields.append(pk_field)  # type: ignore[attr-defined]
+            self.pk_field: BaseField = MultiplePKField(_pk_attrs)
         else:
             assert (
                 len(_pk_attrs) == 1
             ), f"No primary key found in model {self.model.__name__}"
-            self.pk_attr = _pk_attrs[0]
             self._pk_column = getattr(self.model, _pk_attrs[0])
             self._pk_coerce = extract_column_python_type(self._pk_column)  # type: ignore[arg-type]
+            try:
+                # Try to find the primary key field among the fields
+                self.pk_field = next(f for f in self.fields if f.name == _pk_attrs[0])
+            except StopIteration:
+                # If the primary key is not among the fields, treat its value as a string
+                self.pk_field = StringField(_pk_attrs[0])
+        self.pk_attr = self.pk_field.name
 
     async def handle_action(
         self, request: Request, pks: List[Any], name: str

tests/sqla/test_multiple_pks.py

@@ -69,11 +69,9 @@ async def client(app):
         yield c
 
 
-async def test_model_view(session: Session):
+async def test_pk_field(session: Session):
     view = ModelView(Record)
 
-    assert len(view.fields) == 5
-    assert view.pk_field == view.fields[-1]
     assert isinstance(view.pk_field, MultiplePKField)
     assert view.pk_field.name == "id1,id2,id3"
 

tests/sqla/test_view_meta.py

@@ -202,6 +202,23 @@ def test_other_fields_conversion():
     ]
 
 
+def test_pk_field():
+    assert ModelView(Document).pk_field == IntegerField(
+        "int",
+        required=True,
+        exclude_from_create=True,
+        exclude_from_edit=True,
+        help_text="This is the primary key",
+    )
+
+
+def test_pk_field_excluded_from_fields():
+    class DocumentView(ModelView):
+        fields = ["float"]
+
+    assert DocumentView(Document).pk_field == StringField("int")
+
+
 def test_not_supported_array_columns():
     with pytest.raises(
         NotSupportedColumn, match="Column ARRAY with dimensions != 1 is not supported"