[API] Refactor stock adjustment endpoints (#12488)

src/backend/InvenTree/InvenTree/models.py

@@ -76,6 +76,14 @@ class DiffMixin:
             if field.name == 'id':
                 continue
 
+            if field.is_relation:
+                # Compare the raw FK id first (no query) - only dereference to the
+                # full related object (one query each side) if it actually differs.
+                # In the common case (unchanged FK) this avoids two full-object
+                # fetches per relational field for every single save() call.
+                if getattr(self, field.attname) == getattr(db_instance, field.attname):
+                    continue
+
             if getattr(self, field.name) != getattr(db_instance, field.name):
                 deltas[field.name] = {
                     'old': getattr(db_instance, field.name),

src/backend/InvenTree/generic/states/states.py

@@ -282,7 +282,11 @@ class StatusCodeMixin:
 
         - Ensure custom status code values are correctly updated
         """
-        if self.status_class:
+        # Only need to verify the custom key against the DB if one is actually set -
+        # the 'key' column on InvenTreeCustomUserStateModel is non-nullable, so a
+        # query for key=None (i.e. no custom status) can never match and would only
+        # ever result in a no-op (custom_key is already None in that case).
+        if self.status_class and self.get_custom_status() is not None:
             # Check that the current 'logical key' actually matches the current status code
             custom_values = self.status_class.custom_queryset().filter(
                 logical_key=self.get_status(), key=self.get_custom_status()

src/backend/InvenTree/stock/models.py

@@ -1035,11 +1035,19 @@ class StockItem(
         if type(self.batch) is str:
             self.batch = self.batch.strip()
 
-        if not get_global_setting('STOCK_ALLOW_EDIT_SERIAL'):
-            deltas = self.get_field_deltas()
-
+        if not get_global_setting('STOCK_ALLOW_EDIT_SERIAL') and self.pk:
             # Prevent editing of serial numbers if the item already has a serial number assigned
-            if 'serial' in deltas and deltas['serial']['old'] not in [None, '']:
+            # Note: A targeted single-column lookup is used here (rather than get_field_deltas(),
+            # which fetches and diffs *every* field, dereferencing every non-null FK in the
+            # process) since only the previous 'serial' value is actually needed.
+            old_serial = (
+                StockItem.objects
+                .filter(pk=self.pk)
+                .values_list('serial', flat=True)
+                .first()
+            )
+
+            if old_serial not in [None, ''] and old_serial != self.serial:
                 raise ValidationError({
                     'serial': _(
                         'Editing of serial numbers is not allowed - this item has already been assigned a serial number'
@@ -3246,19 +3254,36 @@ class StockItem(
 
         self._apply_model_reference_fields(kwargs, tracking_info)
 
-        quantity_updated = self.serialized or self.updateQuantity(count)
+        # Will updateQuantity() below actually change (and therefore save) the row?
+        # Mirrors updateQuantity()'s own change check - used to decide whether the
+        # stocktake stamp can ride along on that save, avoiding a second write.
+        quantity_will_change = not self.serialized and count != self.quantity
+
+        # Stamp the stocktake metadata *before* updating the quantity, so that when
+        # updateQuantity() performs its own save (below), this stamp - and the status/
+        # location/reference field changes already applied above - are written in that
+        # single query, rather than needing a second, otherwise-redundant save() after.
+        if fields_updated or self.serialized or quantity_will_change:
+            self.stocktake_date = InvenTree.helpers.current_date()
+            self.stocktake_user = user
+
+        raw_update_result = None if self.serialized else self.updateQuantity(count)
+        quantity_updated = self.serialized or raw_update_result
+
+        # True only if updateQuantity() actually performed the save above
+        # (as opposed to: serialized item, no change, or item deleted)
+        update_persisted = raw_update_result is True
 
         # Record the resulting quantity, whether or not this item survived the stocktake
         # (self.quantity is updated by updateQuantity() even if the item was deleted)
         tracking_info['quantity'] = 1 if self.serialized else float(self.quantity)
 
-        # Save if the quantity or any other field was changed.
+        # Save if the quantity or any other field was changed, and updateQuantity()
+        # didn't already do so above.
         # Note that updateQuantity() may have *deleted* the item (depleted to zero),
         # in which case there is nothing left to save.
         if self.pk and (quantity_updated or fields_updated):
-            self.stocktake_date = InvenTree.helpers.current_date()
-            self.stocktake_user = user
-
+            if not update_persisted:
                 self.save(add_note=False)
 
             trigger_event(
@@ -3312,6 +3337,14 @@ class StockItem(
         self._apply_status_change(status, tracking_info)
         self._apply_model_reference_fields(kwargs, tracking_info)
 
+        # Determine up-front whether any optional fields will actually change,
+        # so we can skip the second save() below when updateQuantity() (which
+        # already writes the full row, including the status/reference field
+        # changes applied above) has already persisted everything that matters.
+        optional_fields_changed = any(
+            field in kwargs for field in StockItem.optional_transfer_fields()
+        )
+
         if self.updateQuantity(self.quantity + quantity):
             tracking_info['added'] = float(quantity)
             tracking_info['quantity'] = float(self.quantity)
@@ -3319,6 +3352,7 @@ class StockItem(
             # Optional fields which can be supplied in a 'stocktake' call
             self._apply_optional_transfer_fields(kwargs, tracking_info)
 
+            if optional_fields_changed:
                 self.save(add_note=False)
 
             self.add_tracking_entry(
@@ -3372,6 +3406,14 @@ class StockItem(
         self._apply_status_change(status, deltas)
         self._apply_model_reference_fields(kwargs, deltas)
 
+        # Determine up-front whether any optional fields will actually change,
+        # so we can skip the second save() below when updateQuantity() (which
+        # already writes the full row, including the status/reference field
+        # changes applied above) has already persisted everything that matters.
+        optional_fields_changed = any(
+            field in kwargs for field in StockItem.optional_transfer_fields()
+        )
+
         quantity_updated = self.updateQuantity(self.quantity - quantity)
 
         # Record the resulting quantity, whether or not this item survived the removal
@@ -3383,6 +3425,7 @@ class StockItem(
             # Optional fields which can be supplied in a 'stocktake' call
             self._apply_optional_transfer_fields(kwargs, deltas)
 
+            if optional_fields_changed:
                 self.save(add_note=False)
 
         # Always record a tracking entry, even if the item was deleted as a result

src/backend/InvenTree/stock/serializers.py

@@ -1979,7 +1979,10 @@ class StockAdjustmentSerializer(serializers.Serializer):
 
         if pks:
             self.context['_stockitems'] = {
-                obj.pk: obj for obj in StockItem.objects.filter(pk__in=pks)
+                obj.pk: obj
+                for obj in StockItem.objects.filter(pk__in=pks).select_related(
+                    'part', 'location'
+                )
             }
 
         return super().to_internal_value(data)

src/backend/InvenTree/stock/test_api.py

@@ -3092,9 +3092,8 @@ class StocktakeTest(StockAPITestCase):
         with self.settings(
             PLUGIN_TESTING_EVENTS=True, PLUGIN_TESTING_EVENTS_ASYNC=True
         ):
-            # TODO: 2026-07-12 : Refactor this API call
             response = self.post(
-                url, data, max_query_count=2250, benchmark=True, format='json'
+                url, data, max_query_count=950, benchmark=True, format='json'
             )
 
         self.assertEqual(response.status_code, 201)
@@ -3123,9 +3122,8 @@ class StocktakeTest(StockAPITestCase):
         with self.settings(
             PLUGIN_TESTING_EVENTS=True, PLUGIN_TESTING_EVENTS_ASYNC=True
         ):
-            # TODO: 2026-07-12 : Refactor this API call
             response = self.post(
-                url, data, max_query_count=2500, benchmark=True, format='json'
+                url, data, max_query_count=950, benchmark=True, format='json'
             )
 
         self.assertEqual(response.status_code, 201)
@@ -3154,9 +3152,8 @@ class StocktakeTest(StockAPITestCase):
         with self.settings(
             PLUGIN_TESTING_EVENTS=True, PLUGIN_TESTING_EVENTS_ASYNC=True
         ):
-            # TODO: 2026-07-12 : Refactor this API call
             response = self.post(
-                url, data, max_query_count=2250, benchmark=True, format='json'
+                url, data, max_query_count=950, benchmark=True, format='json'
             )
 
         self.assertEqual(response.status_code, 201)
@@ -3191,9 +3188,8 @@ class StocktakeTest(StockAPITestCase):
         with self.settings(
             PLUGIN_TESTING_EVENTS=True, PLUGIN_TESTING_EVENTS_ASYNC=True
         ):
-            # TODO: 2026-07-12 : Refactor this API call
             response = self.post(
-                url, data, max_query_count=1250, benchmark=True, format='json'
+                url, data, max_query_count=850, benchmark=True, format='json'
             )
 
         self.assertEqual(response.status_code, 201)