[refactor] Optional prefetch (#11012)

* Automatic prefetch of related fields for enable_filter

- Allows us to *not* prefetch fields (expensive) when they are not going to be used
- Enables re-usable components for common detail fields

* Refactor "project_code_detail" filter into common component

- Automatically apply correct prefetch fields

* Refactor 'parameters' annotation

- add 'enable_parameters_filter' function
- Prefetch parameters only when needed
- Refactor / consolidate code

* Refactor SupplierPartSerializer

- Make fields switchable
- Ensure correct prefetch_related

* Refactor serializer for ManufacturerPart

* Refactor BuildSerializer

* Refactor PurchaseOrderSerializer

* Refactor SalesOrderSerializer

* Refactor ReturnOrderSerializer

* Remove debug statements

* Tweaks

* Simplify custom filterable fields

* Bump API version

* Fix for data export

* Additional unit tests

* Remove unused "prefetch_func" option

* Refactor PurchaseOrderLineItemList

* Refactor SalesOrderLineItemList

* Refactor ReturnOrderLineItem

* Cleanup "pretty_name"

* Fix for build list

* Refactoring StockItem API endpoint

- Needs significant work still

* Refactoring for BuildLineSerializer

* Keep all optional fields when exporting data

* Improve "UserRoles" API endpoint

- Prefetch roles
- Prevents significant number of db hits

* Prefetch Parameter API list

* Bug fix for exporting logic

* Specify InvenTreeOutputOption

* Optional prefetch for primary_address

* Fix typing

* Fix unit test

* fixes for playwright tests

* Update Part API

- Improved prefetching

* Fix for prefetch

src/backend/InvenTree/InvenTree/api_version.py

@@ -1,11 +1,17 @@
 """InvenTree API version information."""
 
 # InvenTree API version
-INVENTREE_API_VERSION = 431
+INVENTREE_API_VERSION = 432
 """Increment this API version number whenever there is a significant change to the API that any clients need to know about."""
 
 INVENTREE_API_TEXT = """
 
+v432 -> 2025-12-15 : https://github.com/inventree/InvenTree/pull/11012
+    - The "part_detail" field on the SupplierPart API endpoint is now optional
+    - The "supplier_detail" field on the SupplierPart API endpoint is now optional
+    - The "manufacturer_detail" field on the ManufacturerPart API endpoint is now optional
+    - The "part_detail" field on the StockItem API is now disabled by default
+
 v431 -> 2025-12-14 : https://github.com/inventree/InvenTree/pull/11006
     - Remove duplicate "address" field on the Company API endpoint
     - Make "primary_address" field optional on the Company API endpoint

src/backend/InvenTree/InvenTree/mixins.py

@@ -258,6 +258,19 @@ class OutputOptionsMixin:
 
         return serializer
 
+    def get_queryset(self):
+        """Return the queryset with output options applied.
+
+        This automatically applies any prefetching defined against the optional fields.
+        """
+        queryset = super().get_queryset()
+        serializer = self.get_serializer()
+
+        if isinstance(serializer, FilterableSerializerMixin):
+            queryset = serializer.prefetch_queryset(queryset)
+
+        return queryset
+
 
 class SerializerContextMixin:
     """Mixin to add context to serializer."""

src/backend/InvenTree/InvenTree/serializers.py

@@ -10,6 +10,7 @@ from django.conf import settings
 from django.contrib.contenttypes.models import ContentType
 from django.core.exceptions import ValidationError as DjangoValidationError
 from django.db import models
+from django.db.models import QuerySet
 from django.utils.translation import gettext_lazy as _
 
 from djmoney.contrib.django_rest_framework.fields import MoneyField
@@ -44,11 +45,15 @@ class FilterableSerializerField:
     is_filterable = None
     is_filterable_vals = {}
 
+    # Options for automatic queryset prefetching
+    prefetch_fields: Optional[list[str]] = None
+
     def __init__(self, *args, **kwargs):
         """Initialize the serializer."""
-        if self.is_filterable is None:  # Materialize parameters for later usage
         self.is_filterable = kwargs.pop('is_filterable', None)
         self.is_filterable_vals = kwargs.pop('is_filterable_vals', {})
+        self.prefetch_fields = kwargs.pop('prefetch_fields', None)
+
         super().__init__(*args, **kwargs)
 
 
@@ -57,6 +62,7 @@ def enable_filter(
     default_include: bool = False,
     filter_name: Optional[str] = None,
     filter_by_query: bool = True,
+    prefetch_fields: Optional[list[str]] = None,
 ):
     """Decorator for marking a serializer field as filterable.
 
@@ -67,6 +73,7 @@ def enable_filter(
         default_include (bool): If True, the field will be included by default unless explicitly excluded. If False, the field will be excluded by default unless explicitly included.
         filter_name (str, optional): The name of the filter parameter to use in the URL. If None, the function name of the (decorated) function will be used.
         filter_by_query (bool): If True, also look for filter parameters in the request query parameters.
+        prefetch_fields (list of str, optional): List of related fields to prefetch when this field is included. This can be used to optimize database queries.
 
     Returns:
         The decorated serializer field, marked as filterable.
@@ -84,6 +91,10 @@ def enable_filter(
         'filter_name': filter_name if filter_name else func.field_name,
         'filter_by_query': filter_by_query,
     }
+
+    # Attach queryset prefetching information
+    func._kwargs['prefetch_fields'] = prefetch_fields
+
     return func
 
 
@@ -113,6 +124,34 @@ class FilterableSerializerMixin:
         super().__init__(*args, **kwargs)
         self.do_filtering()
 
+    def prefetch_queryset(self, queryset: QuerySet) -> QuerySet:
+        """Apply any prefetching to the queryset based on the optionally included fields.
+
+        Args:
+            queryset: The original queryset.
+
+        Returns:
+            The modified queryset with prefetching applied.
+        """
+        # Gather up the set of simple 'prefetch' fields and functions
+        prefetch_fields = set()
+
+        filterable_fields = [
+            field
+            for field in self.fields.values()
+            if getattr(field, 'is_filterable', None)
+        ]
+
+        for field in filterable_fields:
+            if prefetch_names := getattr(field, 'prefetch_fields', None):
+                for pf in prefetch_names:
+                    prefetch_fields.add(pf)
+
+        if prefetch_fields and len(prefetch_fields) > 0:
+            queryset = queryset.prefetch_related(*list(prefetch_fields))
+
+        return queryset
+
     def gather_filters(self, kwargs) -> None:
         """Gather filterable fields through introspection."""
         # Fast exit if this has already been done or would not have any effect
@@ -168,6 +207,10 @@ class FilterableSerializerMixin:
         ):
             return
 
+        # Skip filtering when exporting data - leave all fields intact
+        if getattr(self, '_exporting_data', False):
+            return
+
         # Throw out fields which are not requested (either by default or explicitly)
         for k, v in self.filter_target_values.items():
             # See `enable_filter` where` is_filterable and is_filterable_vals are set

src/backend/InvenTree/build/api.py

@@ -319,15 +319,6 @@ class BuildMixin:
 
         queryset = build.serializers.BuildSerializer.annotate_queryset(queryset)
 
-        queryset = queryset.prefetch_related(
-            'responsible',
-            'issued_by',
-            'build_lines',
-            'part',
-            'part__pricing_data',
-            'project_code',
-        )
-
         return queryset
 
 
@@ -568,26 +559,27 @@ class BuildLineOutputOptions(OutputConfiguration):
         InvenTreeOutputOption(
             'bom_item_detail',
             description='Include detailed information about the BOM item linked to this build line.',
-            default=True,
+            default=False,
         ),
         InvenTreeOutputOption(
             'assembly_detail',
             description='Include brief details of the assembly (parent part) related to the BOM item in this build line.',
-            default=True,
+            default=False,
         ),
         InvenTreeOutputOption(
             'part_detail',
             description='Include detailed information about the specific part being built or consumed in this build line.',
-            default=True,
+            default=False,
         ),
         InvenTreeOutputOption(
             'build_detail',
             description='Include detailed information about the associated build order.',
+            default=False,
         ),
         InvenTreeOutputOption(
             'allocations',
             description='Include allocation details showing which stock items are allocated to this build line.',
-            default=True,
+            default=False,
         ),
     ]
 
@@ -905,6 +897,7 @@ class BuildItemOutputOptions(OutputConfiguration):
         InvenTreeOutputOption('location_detail'),
         InvenTreeOutputOption('stock_detail'),
         InvenTreeOutputOption('build_detail'),
+        InvenTreeOutputOption('supplier_part_detail'),
     ]
 
 
@@ -927,26 +920,9 @@ class BuildItemList(
         """Override the queryset method, to perform custom prefetch."""
         queryset = super().get_queryset()
 
-        queryset = queryset.select_related(
+        queryset = queryset.select_related('install_into').prefetch_related(
-            'build_line',
+            'build_line', 'build_line__build', 'build_line__bom_item'
-            'build_line__build',
+        )
-            'build_line__build__part',
-            'build_line__build__responsible',
-            'build_line__build__issued_by',
-            'build_line__build__project_code',
-            'build_line__build__part__pricing_data',
-            'build_line__bom_item',
-            'build_line__bom_item__part',
-            'build_line__bom_item__sub_part',
-            'install_into',
-            'stock_item',
-            'stock_item__location',
-            'stock_item__part',
-            'stock_item__supplier_part__part',
-            'stock_item__supplier_part__supplier',
-            'stock_item__supplier_part__manufacturer_part',
-            'stock_item__supplier_part__manufacturer_part__manufacturer',
-        ).prefetch_related('stock_item__location__tags', 'stock_item__tags')
 
         return queryset
 

src/backend/InvenTree/build/serializers.py

@@ -22,18 +22,16 @@ from rest_framework import serializers
 from rest_framework.serializers import ValidationError
 
 import build.tasks
-import common.serializers
+import common.filters
 import common.settings
 import company.serializers
 import InvenTree.helpers
 import part.filters
 import part.serializers as part_serializers
-from common.serializers import ProjectCodeSerializer
 from common.settings import get_global_setting
 from generic.states.fields import InvenTreeCustomStatusSerializerMixin
 from InvenTree.mixins import DataImportExportSerializerMixin
 from InvenTree.serializers import (
-    FilterableCharField,
     FilterableSerializerMixin,
     InvenTreeDecimalField,
     InvenTreeModelSerializer,
@@ -124,13 +122,10 @@ class BuildSerializer(
     part_detail = enable_filter(
         part_serializers.PartBriefSerializer(source='part', many=False, read_only=True),
         True,
+        prefetch_fields=['part', 'part__category', 'part__pricing_data'],
     )
 
-    parameters = enable_filter(
+    parameters = common.filters.enable_parameters_filter()
-        common.serializers.ParameterSerializer(many=True, read_only=True),
-        False,
-        filter_name='parameters',
-    )
 
     part_name = serializers.CharField(
         source='part.name', read_only=True, label=_('Part Name')
@@ -144,34 +139,21 @@ class BuildSerializer(
         UserSerializer(source='issued_by', read_only=True),
         True,
         filter_name='user_detail',
+        prefetch_fields=['issued_by'],
     )
 
     responsible_detail = enable_filter(
         OwnerSerializer(source='responsible', read_only=True, allow_null=True),
         True,
         filter_name='user_detail',
+        prefetch_fields=['responsible'],
     )
 
     barcode_hash = serializers.CharField(read_only=True)
 
-    project_code_label = enable_filter(
+    project_code_label = common.filters.enable_project_label_filter()
-        FilterableCharField(
-            source='project_code.code',
-            read_only=True,
-            label=_('Project Code Label'),
-            allow_null=True,
-        ),
-        True,
-        filter_name='project_code_detail',
-    )
 
-    project_code_detail = enable_filter(
+    project_code_detail = common.filters.enable_project_code_filter()
-        ProjectCodeSerializer(
-            source='project_code', many=False, read_only=True, allow_null=True
-        ),
-        True,
-        filter_name='project_code_detail',
-    )
 
     @staticmethod
     def annotate_queryset(queryset):
@@ -192,8 +174,6 @@ class BuildSerializer(
             )
         )
 
-        queryset = Build.annotate_parameters(queryset)
-
         return queryset
 
     def __init__(self, *args, **kwargs):
@@ -1240,6 +1220,7 @@ class BuildItemSerializer(
             pricing=False,
         ),
         True,
+        prefetch_fields=['stock_item__part'],
     )
 
     stock_item_detail = enable_filter(
@@ -1255,6 +1236,13 @@ class BuildItemSerializer(
         ),
         True,
         filter_name='stock_detail',
+        prefetch_fields=[
+            'stock_item',
+            'stock_item__tags',
+            'stock_item__part',
+            'stock_item__supplier_part',
+            'stock_item__supplier_part__manufacturer_part',
+        ],
     )
 
     location = serializers.PrimaryKeyRelatedField(
@@ -1269,6 +1257,7 @@ class BuildItemSerializer(
             allow_null=True,
         ),
         True,
+        prefetch_fields=['stock_item__location', 'stock_item__location__tags'],
     )
 
     build_detail = enable_filter(
@@ -1280,15 +1269,32 @@ class BuildItemSerializer(
             allow_null=True,
         ),
         True,
+        prefetch_fields=[
+            'build_line__build',
+            'build_line__build__part',
+            'build_line__build__responsible',
+            'build_line__build__issued_by',
+            'build_line__build__project_code',
+            'build_line__build__part__pricing_data',
+        ],
     )
 
-    supplier_part_detail = company.serializers.SupplierPartSerializer(
+    supplier_part_detail = enable_filter(
+        company.serializers.SupplierPartSerializer(
             label=_('Supplier Part'),
             source='stock_item.supplier_part',
             many=False,
             read_only=True,
             allow_null=True,
             brief=True,
+        ),
+        False,
+        prefetch_fields=[
+            'stock_item__supplier_part',
+            'stock_item__supplier_part__supplier',
+            'stock_item__supplier_part__manufacturer_part',
+            'stock_item__supplier_part__manufacturer_part__manufacturer',
+        ],
     )
 
     quantity = InvenTreeDecimalField(label=_('Allocated Quantity'))
@@ -1373,7 +1379,18 @@ class BuildLineSerializer(
     )
 
     allocations = enable_filter(
-        BuildItemSerializer(many=True, read_only=True, build_detail=False), True
+        BuildItemSerializer(many=True, read_only=True, build_detail=False),
+        True,
+        prefetch_fields=[
+            'allocations',
+            'allocations__stock_item',
+            'allocations__stock_item__part',
+            'allocations__stock_item__part__pricing_data',
+            'allocations__stock_item__supplier_part',
+            'allocations__stock_item__supplier_part__manufacturer_part',
+            'allocations__stock_item__location',
+            'allocations__stock_item__tags',
+        ],
     )
 
     # BOM item info fields
@@ -1417,7 +1434,7 @@ class BuildLineSerializer(
             part_detail=False,
             can_build=False,
         ),
-        True,
+        False,
     )
 
     assembly_detail = enable_filter(
@@ -1429,7 +1446,8 @@ class BuildLineSerializer(
             allow_null=True,
             pricing=False,
         ),
-        True,
+        False,
+        prefetch_fields=['bom_item__part', 'bom_item__part__pricing_data'],
     )
 
     part_detail = enable_filter(
@@ -1440,7 +1458,8 @@ class BuildLineSerializer(
             read_only=True,
             pricing=False,
         ),
-        True,
+        False,
+        prefetch_fields=['bom_item__sub_part', 'bom_item__sub_part__pricing_data'],
     )
 
     category_detail = enable_filter(
@@ -1452,6 +1471,7 @@ class BuildLineSerializer(
             allow_null=True,
         ),
         False,
+        prefetch_fields=['bom_item__sub_part__category'],
     )
 
     build_detail = enable_filter(
@@ -1517,77 +1537,16 @@ class BuildLineSerializer(
             'bom_item__sub_part__pricing_data',
         )
 
-        # Pre-fetch related fields
-        queryset = queryset.prefetch_related(
-            'allocations',
-            'allocations__stock_item',
-            'allocations__stock_item__part',
-            'allocations__stock_item__supplier_part',
-            'allocations__stock_item__supplier_part__manufacturer_part',
-            'allocations__stock_item__location',
-            'allocations__stock_item__tags',
-            'bom_item',
-            'bom_item__part',
-            'bom_item__sub_part',
-            'bom_item__sub_part__category',
-            'bom_item__sub_part__stock_items',
-            'bom_item__sub_part__stock_items__allocations',
-            'bom_item__sub_part__stock_items__sales_order_allocations',
-            'bom_item__substitutes',
-            'bom_item__substitutes__part__stock_items',
-            'bom_item__substitutes__part__stock_items__allocations',
-            'bom_item__substitutes__part__stock_items__sales_order_allocations',
-        )
-
         # Defer expensive fields which we do not need for this serializer
 
-        queryset = (
+        queryset = queryset.defer(
-            queryset.defer(
-                'build__lft',
-                'build__rght',
-                'build__level',
-                'build__tree_id',
-                'build__destination',
-                'build__take_from',
-                'build__completed_by',
-                'build__sales_order',
-                'build__parent',
             'build__notes',
             'build__metadata',
-                'build__responsible',
+            'bom_item__metadata',
-                'build__barcode_data',
-                'build__barcode_hash',
-                'build__project_code',
-            )
-            .defer('bom_item__metadata')
-            .defer(
-                'bom_item__part__lft',
-                'bom_item__part__rght',
-                'bom_item__part__level',
-                'bom_item__part__tree_id',
-                'bom_item__part__tags',
             'bom_item__part__notes',
-                'bom_item__part__variant_of',
+            'bom_item__part__metadata',
-                'bom_item__part__revision_of',
-                'bom_item__part__creation_user',
-                'bom_item__part__bom_checked_by',
-                'bom_item__part__default_supplier',
-                'bom_item__part__responsible_owner',
-            )
-            .defer(
-                'bom_item__sub_part__lft',
-                'bom_item__sub_part__rght',
-                'bom_item__sub_part__level',
-                'bom_item__sub_part__tree_id',
-                'bom_item__sub_part__tags',
             'bom_item__sub_part__notes',
-                'bom_item__sub_part__variant_of',
+            'bom_item__sub_part__metadata',
-                'bom_item__sub_part__revision_of',
-                'bom_item__sub_part__creation_user',
-                'bom_item__sub_part__bom_checked_by',
-                'bom_item__sub_part__default_supplier',
-                'bom_item__sub_part__responsible_owner',
-            )
         )
 
         # Annotate the "allocated" quantity

src/backend/InvenTree/common/api.py

@@ -848,7 +848,9 @@ class ParameterTemplateFilter(FilterSet):
 class ParameterTemplateMixin:
     """Mixin class for ParameterTemplate views."""
 
-    queryset = common.models.ParameterTemplate.objects.all()
+    queryset = common.models.ParameterTemplate.objects.all().prefetch_related(
+        'model_type'
+    )
     serializer_class = common.serializers.ParameterTemplateSerializer
     permission_classes = [IsAuthenticatedOrReadScope]
 
@@ -891,7 +893,9 @@ class ParameterFilter(FilterSet):
 class ParameterMixin:
     """Mixin class for Parameter views."""
 
-    queryset = common.models.Parameter.objects.all()
+    queryset = common.models.Parameter.objects.all().prefetch_related(
+        'model_type', 'updated_by', 'template', 'template__model_type'
+    )
     serializer_class = common.serializers.ParameterSerializer
     permission_classes = [IsAuthenticatedOrReadScope]
 

src/backend/InvenTree/common/filters.py

@@ -17,9 +17,11 @@ from django.db.models import (
     When,
 )
 from django.db.models.query import QuerySet
+from django.utils.translation import gettext_lazy as _
 
 import InvenTree.conversion
 import InvenTree.helpers
+import InvenTree.serializers
 
 
 def determine_content_type(content_type: str | int | None) -> ContentType | None:
@@ -310,3 +312,71 @@ def order_by_parameter(
         f'{prefix}parameter_value_numeric',
         f'{prefix}parameter_value',
     )
+
+
+def enable_project_code_filter(default: bool = True):
+    """Add an optional 'project_code_detail' field to an API serializer.
+
+    Arguments:
+        filter_name: The name of the filter field.
+        default: If True, enable the filter by default.
+
+    If applied, this field will automatically prefetch the 'project_code' relationship.
+    """
+    from common.serializers import ProjectCodeSerializer
+
+    return InvenTree.serializers.enable_filter(
+        ProjectCodeSerializer(
+            source='project_code', many=False, read_only=True, allow_null=True
+        ),
+        default,
+        filter_name='project_code_detail',
+        prefetch_fields=['project_code'],
+    )
+
+
+def enable_project_label_filter(default: bool = True):
+    """Add an optional 'project_code_label' field to an API serializer.
+
+    Arguments:
+        filter_name: The name of the filter field.
+        default: If True, enable the filter by default.
+
+    If applied, this field will automatically prefetch the 'project_code' relationship.
+    """
+    return InvenTree.serializers.enable_filter(
+        InvenTree.serializers.FilterableCharField(
+            source='project_code.code',
+            read_only=True,
+            label=_('Project Code Label'),
+            allow_null=True,
+        ),
+        default,
+        filter_name='project_code_detail',
+        prefetch_fields=['project_code'],
+    )
+
+
+def enable_parameters_filter():
+    """Add an optional 'parameters' field to an API serializer.
+
+    Arguments:
+        source: The source field for the serializer.
+        filter_name: The name of the filter field.
+        default: If True, enable the filter by default.
+
+    If applied, this field will automatically annotate the queryset with parameter data.
+    """
+    from common.serializers import ParameterSerializer
+
+    return InvenTree.serializers.enable_filter(
+        ParameterSerializer(many=True, read_only=True, allow_null=True),
+        False,
+        filter_name='parameters',
+        prefetch_fields=[
+            'parameters_list',
+            'parameters_list__model_type',
+            'parameters_list__updated_by',
+            'parameters_list__template',
+        ],
+    )

src/backend/InvenTree/company/api.py

@@ -178,11 +178,7 @@ class ManufacturerPartMixin(SerializerContextMixin):
         """Return annotated queryset for the ManufacturerPart list endpoint."""
         queryset = super().get_queryset(*args, **kwargs)
 
-        queryset = queryset.prefetch_related(
+        queryset = queryset.prefetch_related('supplier_parts', 'tags')
-            'part', 'manufacturer', 'supplier_parts', 'tags'
-        )
-
-        queryset = ManufacturerPart.annotate_parameters(queryset)
 
         return queryset
 
@@ -304,13 +300,18 @@ class SupplierPartOutputOptions(OutputConfiguration):
         InvenTreeOutputOption(
             description='Include detailed information about the Supplier in the response',
             flag='supplier_detail',
-            default=True,
+            default=False,
         ),
         InvenTreeOutputOption(
             description='Include detailed information about the Manufacturer in the response',
             flag='manufacturer_detail',
             default=False,
         ),
+        InvenTreeOutputOption(
+            flag='manufacturer_part_detail',
+            description='Include detailed information about the linked ManufacturerPart in the response',
+            default=False,
+        ),
         InvenTreeOutputOption(
             description='Format the output with a more readable (pretty) name',
             flag='pretty',

src/backend/InvenTree/company/serializers.py

@@ -10,7 +10,7 @@ from rest_framework import serializers
 from sql_util.utils import SubqueryCount
 from taggit.serializers import TagListSerializerField
 
-import common.serializers
+import common.filters
 import company.filters
 import part.filters
 import part.serializers as part_serializers
@@ -163,22 +163,19 @@ class CompanySerializer(
 
         queryset = queryset.annotate(parts_supplied=SubqueryCount('supplied_parts'))
 
-        queryset = queryset.prefetch_related(
+        return queryset
+
+    primary_address = enable_filter(
+        AddressBriefSerializer(read_only=True, allow_null=True),
+        False,
+        filter_name='address_detail',
+        prefetch_fields=[
             Prefetch(
                 'addresses',
                 queryset=Address.objects.filter(primary=True),
                 to_attr='primary_address_list',
             )
-        )
+        ],
-
-        queryset = Company.annotate_parameters(queryset)
-
-        return queryset
-
-    primary_address = enable_filter(
-        AddressBriefSerializer(read_only=True, allow_null=True),
-        True,
-        filter_name='address_detail',
     )
 
     image = InvenTreeImageSerializerField(required=False, allow_null=True)
@@ -195,11 +192,7 @@ class CompanySerializer(
         help_text=_('Default currency used for this supplier'), required=True
     )
 
-    parameters = enable_filter(
+    parameters = common.filters.enable_parameters_filter()
-        common.serializers.ParameterSerializer(many=True, read_only=True),
-        False,
-        filter_name='parameters',
-    )
 
     def save(self):
         """Save the Company instance."""
@@ -269,24 +262,14 @@ class ManufacturerPartSerializer(
 
     tags = TagListSerializerField(required=False)
 
-    parameters = enable_filter(
+    parameters = common.filters.enable_parameters_filter()
-        common.serializers.ParameterSerializer(many=True, read_only=True),
-        False,
-        filter_name='parameters',
-    )
 
     part_detail = enable_filter(
         part_serializers.PartBriefSerializer(
             source='part', many=False, read_only=True, allow_null=True
         ),
         True,
-    )
+        prefetch_fields=['part'],
-
-    manufacturer_detail = enable_filter(
-        CompanyBriefSerializer(
-            source='manufacturer', many=False, read_only=True, allow_null=True
-        ),
-        True,
     )
 
     pretty_name = enable_filter(
@@ -297,6 +280,14 @@ class ManufacturerPartSerializer(
         queryset=Company.objects.filter(is_manufacturer=True)
     )
 
+    manufacturer_detail = enable_filter(
+        CompanyBriefSerializer(
+            source='manufacturer', many=False, read_only=True, allow_null=True
+        ),
+        True,
+        prefetch_fields=['manufacturer'],
+    )
+
 
 class SupplierPriceBreakBriefSerializer(
     FilterableSerializerMixin, InvenTreeModelSerializer
@@ -399,33 +390,13 @@ class SupplierPartSerializer(
         # Check if 'available' quantity was supplied
         self.has_available_quantity = 'available' in kwargs.get('data', {})
 
-        # TODO INVE-T1 support complex filters
         brief = kwargs.pop('brief', False)
-        detail_default = not brief
-        part_detail = kwargs.pop('part_detail', detail_default)
-        supplier_detail = kwargs.pop('supplier_detail', detail_default)
-        manufacturer_detail = kwargs.pop('manufacturer_detail', detail_default)
-
-        prettify = kwargs.pop('pretty', False)
 
         super().__init__(*args, **kwargs)
 
         if isGeneratingSchema():
             return
 
-        if part_detail is not True:
-            self.fields.pop('part_detail', None)
-
-        if supplier_detail is not True:
-            self.fields.pop('supplier_detail', None)
-
-        if manufacturer_detail is not True:
-            self.fields.pop('manufacturer_detail', None)
-            self.fields.pop('manufacturer_part_detail', None)
-
-        if brief or prettify is not True:
-            self.fields.pop('pretty_name', None)
-
         if brief:
             self.fields.pop('tags')
             self.fields.pop('available')
@@ -455,46 +426,61 @@ class SupplierPartSerializer(
         ),
         False,
         filter_name='price_breaks',
+        prefetch_fields=['pricebreaks'],
     )
 
-    parameters = enable_filter(
+    parameters = common.filters.enable_parameters_filter()
-        common.serializers.ParameterSerializer(many=True, read_only=True),
-        False,
-        filter_name='parameters',
-    )
 
-    part_detail = part_serializers.PartBriefSerializer(
+    part_detail = enable_filter(
+        part_serializers.PartBriefSerializer(
             label=_('Part'), source='part', many=False, read_only=True, allow_null=True
+        ),
+        False,
+        prefetch_fields=['part'],
     )
 
-    supplier_detail = CompanyBriefSerializer(
+    supplier_detail = enable_filter(
+        CompanyBriefSerializer(
             label=_('Supplier'),
             source='supplier',
             many=False,
             read_only=True,
             allow_null=True,
+        ),
+        False,
+        prefetch_fields=['supplier'],
     )
 
-    manufacturer_detail = CompanyBriefSerializer(
+    manufacturer_detail = enable_filter(
+        CompanyBriefSerializer(
             label=_('Manufacturer'),
             source='manufacturer_part.manufacturer',
             many=False,
             read_only=True,
             allow_null=True,
+        ),
+        False,
+        prefetch_fields=['manufacturer_part__manufacturer'],
     )
 
-    pretty_name = serializers.CharField(read_only=True, allow_null=True)
+    pretty_name = enable_filter(
+        FilterableCharField(read_only=True, allow_null=True), filter_name='pretty'
+    )
 
     supplier = serializers.PrimaryKeyRelatedField(
         label=_('Supplier'), queryset=Company.objects.filter(is_supplier=True)
     )
 
-    manufacturer_part_detail = ManufacturerPartSerializer(
+    manufacturer_part_detail = enable_filter(
+        ManufacturerPartSerializer(
             label=_('Manufacturer Part'),
             source='manufacturer_part',
             part_detail=False,
             read_only=True,
             allow_null=True,
+        ),
+        False,
+        prefetch_fields=['manufacturer_part'],
     )
 
     MPN = serializers.CharField(
@@ -511,15 +497,13 @@ class SupplierPartSerializer(
         Fields:
             in_stock: Current stock quantity for each SupplierPart
         """
-        queryset = queryset.prefetch_related('part', 'pricebreaks')
-
         queryset = queryset.annotate(in_stock=part.filters.annotate_total_stock())
 
         queryset = queryset.annotate(
             on_order=company.filters.annotate_on_order_quantity()
         )
 
-        queryset = SupplierPart.annotate_parameters(queryset)
+        queryset = queryset.prefetch_related('supplier', 'manufacturer_part')
 
         return queryset
 

src/backend/InvenTree/company/test_api.py

@@ -210,6 +210,34 @@ class CompanyTest(InvenTreeAPITestCase):
 
             self.assertEqual(response.data['notes'], note)
 
+    def test_company_parameters(self):
+        """Test for annotation of 'parameters' field in Company API."""
+        url = reverse('api-company-list')
+
+        response = self.get(url, expected_code=200)
+
+        self.assertGreater(len(response.data), 0)
+
+        # Default = not included
+        for result in response.data:
+            self.assertNotIn('parameters', result)
+
+        # Exclude parameters
+        response = self.get(url, {'parameters': 'false'}, expected_code=200)
+
+        self.assertGreater(len(response.data), 0)
+
+        for result in response.data:
+            self.assertNotIn('parameters', result)
+
+        # Include parameters
+        response = self.get(url, {'parameters': 'true'}, expected_code=200)
+
+        self.assertGreater(len(response.data), 0)
+
+        for result in response.data:
+            self.assertIn('parameters', result)
+
 
 class ContactTest(InvenTreeAPITestCase):
     """Tests for the Contact models."""
@@ -682,6 +710,42 @@ class SupplierPartTest(InvenTreeAPITestCase):
         for result in response.data:
             self.assertEqual(result['supplier'], company.pk)
 
+    def test_filterable_fields(self):
+        """Test inclusion/exclusion of optional API fields."""
+        fields = {
+            'price_breaks': False,
+            'part_detail': False,
+            'supplier_detail': False,
+            'manufacturer_detail': False,
+            'manufacturer_part_detail': False,
+        }
+
+        url = reverse('api-supplier-part-list')
+
+        for field, included in fields.items():
+            # Test default behavior
+            response = self.get(url, data={}, expected_code=200)
+            self.assertGreater(len(response.data), 0)
+            self.assertEqual(
+                included,
+                field in response.data[0],
+                f'Field: {field} failed default test',
+            )
+
+            # Test explicit inclusion
+            response = self.get(url, data={field: 'true'}, expected_code=200)
+            self.assertGreater(len(response.data), 0)
+            self.assertIn(
+                field, response.data[0], f'Field: {field} failed inclusion test'
+            )
+
+            # Test explicit exclusion
+            response = self.get(url, data={field: 'false'}, expected_code=200)
+            self.assertGreater(len(response.data), 0)
+            self.assertNotIn(
+                field, response.data[0], f'Field: {field} failed exclusion test'
+            )
+
 
 class CompanyMetadataAPITest(InvenTreeAPITestCase):
     """Unit tests for the various metadata endpoints of API."""

src/backend/InvenTree/data_exporter/mixins.py

@@ -53,7 +53,7 @@ class DataExportSerializerMixin:
         Determine if the serializer is being used for data export,
         and if so, adjust the serializer fields accordingly.
         """
-        exporting = kwargs.pop('exporting', False)
+        self._exporting_data = exporting = kwargs.pop('exporting', False)
 
         super().__init__(*args, **kwargs)
 
@@ -264,10 +264,8 @@ class DataExportViewMixin:
         exporting = kwargs.pop('exporting', None)
 
         if exporting is None:
-            exporting = (
+            method = str(getattr(self.request, 'method', '')).lower()
-                self.request.method.lower() in ['options', 'get']
+            exporting = method in ['options', 'get'] and self.is_exporting()
-                and self.is_exporting()
-            )
 
         if exporting:
             # Override kwargs when initializing the DataExportOptionsSerializer

src/backend/InvenTree/order/api.py

@@ -369,12 +369,10 @@ class PurchaseOrderMixin(SerializerContextMixin):
         """Return the annotated queryset for this endpoint."""
         queryset = super().get_queryset(*args, **kwargs)
 
-        queryset = queryset.prefetch_related(
-            'supplier', 'project_code', 'lines', 'responsible'
-        )
-
         queryset = serializers.PurchaseOrderSerializer.annotate_queryset(queryset)
 
+        queryset = queryset.prefetch_related('supplier', 'created_by')
+
         return queryset
 
 
@@ -833,9 +831,7 @@ class SalesOrderMixin(SerializerContextMixin):
         """Return annotated queryset for this endpoint."""
         queryset = super().get_queryset(*args, **kwargs)
 
-        queryset = queryset.prefetch_related(
+        queryset = queryset.prefetch_related('customer', 'created_by')
-            'customer', 'responsible', 'project_code', 'lines'
-        )
 
         queryset = serializers.SalesOrderSerializer.annotate_queryset(queryset)
 
@@ -1018,17 +1014,13 @@ class SalesOrderLineItemMixin(SerializerContextMixin):
 
         queryset = queryset.prefetch_related(
             'part',
-            'part__stock_items',
             'allocations',
             'allocations__shipment',
             'allocations__item__part',
             'allocations__item__location',
             'order',
-            'order__stock_items',
         )
 
-        queryset = queryset.select_related('part__pricing_data')
-
         queryset = serializers.SalesOrderLineItemSerializer.annotate_queryset(queryset)
 
         return queryset
@@ -1510,9 +1502,7 @@ class ReturnOrderMixin(SerializerContextMixin):
         """Return annotated queryset for this endpoint."""
         queryset = super().get_queryset(*args, **kwargs)
 
-        queryset = queryset.prefetch_related(
+        queryset = queryset.prefetch_related('customer', 'created_by')
-            'customer', 'lines', 'project_code', 'responsible'
-        )
 
         queryset = serializers.ReturnOrderSerializer.annotate_queryset(queryset)
 

src/backend/InvenTree/order/models.py

@@ -1989,17 +1989,16 @@ class PurchaseOrderLineItem(OrderLineItem):
     def get_destination(self):
         """Show where the line item is or should be placed.
 
-        NOTE: If a line item gets split when received, only an arbitrary
+        1. If a destination is specified against this line item, return that.
-              stock items location will be reported as the location for the
+        2. If a destination is specified against the PurchaseOrderPart, return that.
-              entire line.
+        3. If a default location is specified against the linked Part, return that.
         """
-        for item in stock.models.StockItem.objects.filter(
-            supplier_part=self.part, purchase_order=self.order
-        ):
-            if item.location:
-                return item.location
         if self.destination:
             return self.destination
+
+        if self.order.destination:
+            return self.order.destination
+
         if self.part and self.part.part and self.part.part.default_location:
             return self.part.part.default_location
 

src/backend/InvenTree/order/serializers.py

@@ -4,16 +4,7 @@ from decimal import Decimal
 
 from django.core.exceptions import ValidationError as DjangoValidationError
 from django.db import models, transaction
-from django.db.models import (
+from django.db.models import BooleanField, Case, ExpressionWrapper, F, Q, Value, When
-    BooleanField,
-    Case,
-    ExpressionWrapper,
-    F,
-    Prefetch,
-    Q,
-    Value,
-    When,
-)
 from django.db.models.functions import Coalesce, Greatest
 from django.utils.translation import gettext_lazy as _
 
@@ -22,13 +13,12 @@ from rest_framework.serializers import ValidationError
 from sql_util.utils import SubqueryCount, SubquerySum
 
 import build.serializers
-import common.serializers
+import common.filters
 import order.models
 import part.filters as part_filters
 import part.models as part_models
 import stock.models
 import stock.serializers
-from common.serializers import ProjectCodeSerializer
 from company.serializers import (
     AddressBriefSerializer,
     CompanyBriefSerializer,
@@ -46,7 +36,6 @@ from InvenTree.helpers import (
 )
 from InvenTree.mixins import DataImportExportSerializerMixin
 from InvenTree.serializers import (
-    FilterableCharField,
     FilterableSerializerMixin,
     InvenTreeCurrencySerializer,
     InvenTreeDecimalField,
@@ -141,6 +130,7 @@ class AbstractOrderSerializer(
             source='contact', many=False, read_only=True, allow_null=True
         ),
         True,
+        prefetch_fields=['contact'],
     )
 
     # Detail for responsible field
@@ -149,26 +139,11 @@ class AbstractOrderSerializer(
             source='responsible', read_only=True, allow_null=True, many=False
         ),
         True,
+        prefetch_fields=['responsible'],
     )
 
-    project_code_label = enable_filter(
+    project_code_label = common.filters.enable_project_label_filter()
-        FilterableCharField(
+    project_code_detail = common.filters.enable_project_code_filter()
-            source='project_code.code',
-            read_only=True,
-            label='Project Code Label',
-            allow_null=True,
-        ),
-        True,
-        filter_name='project_code_detail',
-    )
-
-    # Detail for project code field
-    project_code_detail = enable_filter(
-        ProjectCodeSerializer(
-            source='project_code', read_only=True, many=False, allow_null=True
-        ),
-        True,
-    )
 
     # Detail for address field
     address_detail = enable_filter(
@@ -176,13 +151,10 @@ class AbstractOrderSerializer(
             source='address', many=False, read_only=True, allow_null=True
         ),
         True,
+        prefetch_fields=['address'],
     )
 
-    parameters = enable_filter(
+    parameters = common.filters.enable_parameters_filter()
-        common.serializers.ParameterSerializer(many=True, read_only=True),
-        False,
-        filter_name='parameters',
-    )
 
     # Boolean field indicating if this order is overdue (Note: must be annotated)
     overdue = serializers.BooleanField(read_only=True, allow_null=True)
@@ -317,23 +289,9 @@ class AbstractLineItemSerializer(FilterableSerializerMixin, serializers.Serializ
         required=False, allow_null=True, label=_('Target Date')
     )
 
-    project_code_label = enable_filter(
+    project_code_label = common.filters.enable_project_label_filter()
-        FilterableCharField(
-            source='project_code.code',
-            read_only=True,
-            label='Project Code Label',
-            allow_null=True,
-        ),
-        True,
-        filter_name='project_code_detail',
-    )
 
-    project_code_detail = enable_filter(
+    project_code_detail = common.filters.enable_project_code_filter()
-        ProjectCodeSerializer(
-            source='project_code', read_only=True, many=False, allow_null=True
-        ),
-        True,
-    )
 
 
 class AbstractExtraLineSerializer(
@@ -369,24 +327,9 @@ class AbstractExtraLineSerializer(
 
     price_currency = InvenTreeCurrencySerializer()
 
-    project_code_label = enable_filter(
+    project_code_label = common.filters.enable_project_label_filter()
-        FilterableCharField(
-            source='project_code.code',
-            read_only=True,
-            label='Project Code Label',
-            allow_null=True,
-        ),
-        True,
-        filter_name='project_code_detail',
-    )
 
-    # Detail for project code field
+    project_code_detail = common.filters.enable_project_code_filter()
-    project_code_detail = enable_filter(
-        ProjectCodeSerializer(
-            source='project_code', read_only=True, many=False, allow_null=True
-        ),
-        True,
-    )
 
 
 class AbstractExtraLineMeta:
@@ -452,9 +395,6 @@ class PurchaseOrderSerializer(
         """
         queryset = AbstractOrderSerializer.annotate_queryset(queryset)
 
-        # Annotate parametric data
-        queryset = order.models.PurchaseOrder.annotate_parameters(queryset)
-
         queryset = queryset.annotate(
             completed_lines=SubqueryCount(
                 'lines', filter=Q(quantity__lte=F('received'))
@@ -471,6 +411,8 @@ class PurchaseOrderSerializer(
             )
         )
 
+        queryset = queryset.prefetch_related('created_by')
+
         return queryset
 
     supplier_name = serializers.CharField(
@@ -480,7 +422,8 @@ class PurchaseOrderSerializer(
     supplier_detail = enable_filter(
         CompanyBriefSerializer(
             source='supplier', many=False, read_only=True, allow_null=True
-        )
+        ),
+        prefetch_fields=['supplier'],
     )
 
 
@@ -612,27 +555,18 @@ class PurchaseOrderLineItemSerializer(
         - "total_price" = purchase_price * quantity
         - "overdue" status (boolean field)
         """
-        queryset = queryset.prefetch_related(
-            Prefetch(
-                'part__part',
-                queryset=part_models.Part.objects.annotate(
-                    category_default_location=part_filters.annotate_default_location(
-                        'category__'
-                    )
-                ).prefetch_related(None),
-            )
-        )
-
         queryset = queryset.prefetch_related(
             'order',
             'order__responsible',
             'order__stock_items',
+            'part',
+            'part__part',
+            'part__part__pricing_data',
+            'part__part__default_location',
             'part__tags',
             'part__supplier',
             'part__manufacturer_part',
             'part__manufacturer_part__manufacturer',
-            'part__part__pricing_data',
-            'part__part__tags',
         )
 
         queryset = queryset.annotate(
@@ -687,6 +621,7 @@ class PurchaseOrderLineItemSerializer(
         PartBriefSerializer(
             source='get_base_part', many=False, read_only=True, allow_null=True
         ),
+        False,
         filter_name='part_detail',
     )
 
@@ -694,6 +629,7 @@ class PurchaseOrderLineItemSerializer(
         SupplierPartSerializer(
             source='part', brief=True, many=False, read_only=True, allow_null=True
         ),
+        False,
         filter_name='part_detail',
     )
 
@@ -707,8 +643,12 @@ class PurchaseOrderLineItemSerializer(
         default=True,
     )
 
-    destination_detail = stock.serializers.LocationBriefSerializer(
+    destination_detail = enable_filter(
+        stock.serializers.LocationBriefSerializer(
             source='get_destination', read_only=True, allow_null=True
+        ),
+        True,
+        prefetch_fields=['destination', 'order__destination'],
     )
 
     purchase_price_currency = InvenTreeCurrencySerializer(
@@ -721,8 +661,16 @@ class PurchaseOrderLineItemSerializer(
         )
     )
 
-    build_order_detail = build.serializers.BuildSerializer(
+    build_order_detail = enable_filter(
+        build.serializers.BuildSerializer(
             source='build_order', read_only=True, allow_null=True, many=False
+        ),
+        True,
+        prefetch_fields=[
+            'build_order__responsible',
+            'build_order__issued_by',
+            'build_order__part',
+        ],
     )
 
     merge_items = serializers.BooleanField(
@@ -1098,9 +1046,6 @@ class SalesOrderSerializer(
         """
         queryset = AbstractOrderSerializer.annotate_queryset(queryset)
 
-        # Annotate parametric data
-        queryset = order.models.SalesOrder.annotate_parameters(queryset)
-
         queryset = queryset.annotate(
             completed_lines=SubqueryCount('lines', filter=Q(quantity__lte=F('shipped')))
         )
@@ -1128,7 +1073,8 @@ class SalesOrderSerializer(
     customer_detail = enable_filter(
         CompanyBriefSerializer(
             source='customer', many=False, read_only=True, allow_null=True
-        )
+        ),
+        prefetch_fields=['customer'],
     )
 
     shipments_count = serializers.IntegerField(
@@ -1277,15 +1223,26 @@ class SalesOrderLineItemSerializer(
     order_detail = enable_filter(
         SalesOrderSerializer(
             source='order', many=False, read_only=True, allow_null=True
+        ),
+        prefetch_fields=[
+            'order__created_by',
+            'order__responsible',
+            'order__address',
+            'order__project_code',
+            'order__contact',
+        ],
     )
-    )
+
     part_detail = enable_filter(
-        PartBriefSerializer(source='part', many=False, read_only=True, allow_null=True)
+        PartBriefSerializer(source='part', many=False, read_only=True, allow_null=True),
+        prefetch_fields=['part__pricing_data'],
     )
+
     customer_detail = enable_filter(
         CompanyBriefSerializer(
             source='order.customer', many=False, read_only=True, allow_null=True
-        )
+        ),
+        prefetch_fields=['order__customer'],
     )
 
     # Annotated fields
@@ -1950,9 +1907,6 @@ class ReturnOrderSerializer(
         """Custom annotation for the serializer queryset."""
         queryset = AbstractOrderSerializer.annotate_queryset(queryset)
 
-        # Annotate parametric data
-        queryset = order.models.ReturnOrder.annotate_parameters(queryset)
-
         queryset = queryset.annotate(
             completed_lines=SubqueryCount(
                 'lines', filter=~Q(outcome=ReturnOrderLineStatus.PENDING.value)
@@ -1974,7 +1928,8 @@ class ReturnOrderSerializer(
     customer_detail = enable_filter(
         CompanyBriefSerializer(
             source='customer', many=False, read_only=True, allow_null=True
-        )
+        ),
+        prefetch_fields=['customer'],
     )
 
 
@@ -2134,7 +2089,14 @@ class ReturnOrderLineItemSerializer(
     order_detail = enable_filter(
         ReturnOrderSerializer(
             source='order', many=False, read_only=True, allow_null=True
-        )
+        ),
+        prefetch_fields=[
+            'order__created_by',
+            'order__responsible',
+            'order__address',
+            'order__project_code',
+            'order__contact',
+        ],
     )
 
     quantity = serializers.FloatField(
@@ -2144,7 +2106,8 @@ class ReturnOrderLineItemSerializer(
     item_detail = enable_filter(
         stock.serializers.StockItemSerializer(
             source='item', many=False, read_only=True, allow_null=True
-        )
+        ),
+        prefetch_fields=['item__supplier_part'],
     )
 
     part_detail = enable_filter(

src/backend/InvenTree/part/api.py

@@ -1009,7 +1009,7 @@ class PartMixin(SerializerContextMixin):
     """Mixin class for Part API endpoints."""
 
     serializer_class = part_serializers.PartSerializer
-    queryset = Part.objects.all()
+    queryset = Part.objects.all().select_related('pricing_data')
 
     starred_parts = None
     is_create = False
@@ -1020,9 +1020,6 @@ class PartMixin(SerializerContextMixin):
 
         queryset = part_serializers.PartSerializer.annotate_queryset(queryset)
 
-        if str2bool(self.request.query_params.get('price_breaks', True)):
-            queryset = queryset.prefetch_related('salepricebreaks')
-
         return queryset
 
     def get_serializer(self, *args, **kwargs):

src/backend/InvenTree/part/serializers.py

@@ -9,7 +9,7 @@ from django.core.files.base import ContentFile
 from django.core.validators import MinValueValidator
 from django.db import models, transaction
 from django.db.models import ExpressionWrapper, F, Q
-from django.db.models.functions import Coalesce, Greatest
+from django.db.models.functions import Greatest
 from django.urls import reverse_lazy
 from django.utils.translation import gettext_lazy as _
 
@@ -22,6 +22,7 @@ from sql_util.utils import SubqueryCount
 from taggit.serializers import TagListSerializerField
 
 import common.currency
+import common.filters
 import common.serializers
 import company.models
 import InvenTree.helpers
@@ -619,7 +620,6 @@ class PartSerializer(
             'required_for_build_orders',
             'required_for_sales_orders',
             'stock_item_count',
-            'suppliers',
             'total_in_stock',
             'external_stock',
             'unallocated_stock',
@@ -680,10 +680,6 @@ class PartSerializer(
 
         Performing database queries as efficiently as possible, to reduce database trips.
         """
-        queryset = queryset.prefetch_related('category', 'default_location')
-
-        queryset = Part.annotate_parameters(queryset)
-
         # Annotate with the total number of revisions
         queryset = queryset.annotate(revision_count=SubqueryCount('revisions'))
 
@@ -708,15 +704,6 @@ class PartSerializer(
             scheduled_to_build=part_filters.annotate_scheduled_to_build_quantity()
         )
 
-        # Annotate with the number of 'suppliers'
-        queryset = queryset.annotate(
-            suppliers=Coalesce(
-                SubqueryCount('supplier_parts'),
-                Decimal(0),
-                output_field=models.DecimalField(),
-            )
-        )
-
         queryset = queryset.annotate(
             ordering=part_filters.annotate_on_order_quantity(),
             in_stock=part_filters.annotate_total_stock(),
@@ -775,7 +762,8 @@ class PartSerializer(
     category_detail = enable_filter(
         CategorySerializer(
             source='category', many=False, read_only=True, allow_null=True
-        )
+        ),
+        prefetch_fields=['category'],
     )
 
     category_path = enable_filter(
@@ -786,6 +774,7 @@ class PartSerializer(
             allow_null=True,
         ),
         filter_name='path_detail',
+        prefetch_fields=['category'],
     )
 
     default_location_detail = enable_filter(
@@ -793,6 +782,7 @@ class PartSerializer(
             source='default_location', many=False, read_only=True, allow_null=True
         ),
         filter_name='location_detail',
+        prefetch_fields=['default_location'],
     )
 
     category_name = serializers.CharField(
@@ -860,10 +850,6 @@ class PartSerializer(
         read_only=True, allow_null=True, label=_('Revisions')
     )
 
-    suppliers = serializers.IntegerField(
-        read_only=True, allow_null=True, label=_('Suppliers')
-    )
-
     total_in_stock = serializers.FloatField(
         read_only=True, allow_null=True, label=_('Total Stock')
     )
@@ -922,13 +908,7 @@ class PartSerializer(
         filter_name='pricing',
     )
 
-    parameters = enable_filter(
+    parameters = common.filters.enable_parameters_filter()
-        common.serializers.ParameterSerializer(
-            many=True, read_only=True, allow_null=True
-        ),
-        False,
-        filter_name='parameters',
-    )
 
     price_breaks = enable_filter(
         PartSalePriceSerializer(
@@ -936,6 +916,7 @@ class PartSerializer(
         ),
         False,
         filter_name='price_breaks',
+        prefetch_fields=['salepricebreaks'],
     )
 
     # Extra fields used only for creation of a new Part instance
@@ -963,6 +944,7 @@ class PartSerializer(
     copy_category_parameters = serializers.BooleanField(
         default=True,
         required=False,
+        write_only=True,
         label=_('Copy Category Parameters'),
         help_text=_('Copy parameter templates from selected part category'),
     )

src/backend/InvenTree/stock/serializers.py

@@ -475,9 +475,7 @@ class StockItemSerializer(
         """Add some extra annotations to the queryset, performing database queries as efficiently as possible."""
         queryset = queryset.prefetch_related(
             'location',
-            'allocations',
             'sales_order',
-            'sales_order_allocations',
             'purchase_order',
             Prefetch(
                 'part',
@@ -489,25 +487,15 @@ class StockItemSerializer(
             ),
             'parent',
             'part__category',
-            'part__supplier_parts',
-            'part__supplier_parts__purchase_order_line_items',
             'part__pricing_data',
-            'part__tags',
             'supplier_part',
-            'supplier_part__part',
-            'supplier_part__supplier',
             'supplier_part__manufacturer_part',
-            'supplier_part__manufacturer_part__manufacturer',
-            'supplier_part__manufacturer_part__tags',
-            'supplier_part__purchase_order_line_items',
-            'supplier_part__tags',
-            'test_results',
             'customer',
             'belongs_to',
             'sales_order',
             'consumed_by',
             'tags',
-        )
+        ).select_related('part')
 
         # Annotate the queryset with the total allocated to sales orders
         queryset = queryset.annotate(
@@ -586,7 +574,14 @@ class StockItemSerializer(
             read_only=True,
             allow_null=True,
         ),
-        True,
+        False,
+        prefetch_fields=[
+            'supplier_part__supplier',
+            'supplier_part__manufacturer_part__manufacturer',
+            'supplier_part__manufacturer_part__tags',
+            'supplier_part__purchase_order_line_items',
+            'supplier_part__tags',
+        ],
     )
 
     part_detail = enable_filter(
@@ -604,13 +599,20 @@ class StockItemSerializer(
             read_only=True,
             allow_null=True,
         ),
-        True,
+        False,
+        prefetch_fields=['location'],
     )
 
     tests = enable_filter(
         StockItemTestResultSerializer(
             source='test_results', many=True, read_only=True, allow_null=True
-        )
+        ),
+        False,
+        prefetch_fields=[
+            'test_results',
+            'test_results__user',
+            'test_results__template',
+        ],
     )
 
     quantity = InvenTreeDecimalField()

src/backend/InvenTree/stock/test_api.py

@@ -866,7 +866,9 @@ class StockItemListTest(StockAPITestCase):
 
         excluded_headers = ['metadata']
 
-        with self.export_data(self.list_url) as data_file:
+        filters = {}
+
+        with self.export_data(self.list_url, filters) as data_file:
             self.process_csv(
                 data_file,
                 required_cols=required_headers,
@@ -875,9 +877,10 @@ class StockItemListTest(StockAPITestCase):
             )
 
         # Now, add a filter to the results
-        with self.export_data(
+        filters['location'] = 1
-            self.list_url, {'location': 1, 'cascade': True}
+        filters['cascade'] = True
-        ) as data_file:
+
+        with self.export_data(self.list_url, filters) as data_file:
             data = self.process_csv(data_file, required_rows=9)
 
             for row in data:

src/backend/InvenTree/users/permissions.py

@@ -1,7 +1,10 @@
 """Helper functions for user permission checks."""
 
+from typing import Optional
+
 from django.contrib.auth.models import User
 from django.db import models
+from django.db.models.query import Prefetch, QuerySet
 
 import InvenTree.cache
 from users.ruleset import RULESET_CHANGE_INHERIT, get_ruleset_ignore, get_ruleset_models
@@ -55,8 +58,26 @@ def split_permission(app: str, perm: str) -> tuple[str, str]:
     return perm, model
 
 
+def prefetch_rule_sets(user) -> QuerySet:
+    """Return a queryset of groups with prefetched rule sets for the given user.
+
+    Arguments:
+        user: The user object
+
+    Returns:
+        QuerySet: The queryset of groups with prefetched rule sets
+    """
+    return user.groups.all().prefetch_related(
+        Prefetch('rule_sets', to_attr='prefetched_rule_sets')
+    )
+
+
 def check_user_role(
-    user: User, role: str, permission: str, allow_inactive: bool = False
+    user: User,
+    role: str,
+    permission: str,
+    allow_inactive: bool = False,
+    groups: Optional[QuerySet] = None,
 ) -> bool:
     """Check if a user has a particular role:permission combination.
 
@@ -65,6 +86,7 @@ def check_user_role(
         role: The role to check (e.g. 'part' / 'stock')
         permission: The permission to check (e.g. 'view' / 'delete')
         allow_inactive: If False, disallow inactive users from having permissions
+        groups: Optional cached queryset of groups to check (defaults to user's groups)
 
     Returns:
         bool: True if the user has the specified role:permission combination
@@ -90,8 +112,10 @@ def check_user_role(
     # Default for no match
     result = False
 
-    for group in user.groups.all():
+    groups = groups or prefetch_rule_sets(user)
-        for rule in group.rule_sets.all():
+
+    for group in groups:
+        for rule in group.prefetched_rule_sets:
             if rule.name == role:
                 # Check if the rule has the specified permission
                 # e.g. "view" role maps to "can_view" attribute

src/backend/InvenTree/users/serializers.py

@@ -19,7 +19,7 @@ from InvenTree.serializers import (
 )
 
 from .models import ApiToken, Owner, RuleSet, UserProfile
-from .permissions import check_user_role
+from .permissions import check_user_role, prefetch_rule_sets
 from .ruleset import RULESET_CHOICES, RULESET_PERMISSIONS, RuleSetEnum
 
 
@@ -83,13 +83,16 @@ class RoleSerializer(InvenTreeModelSerializer):
         """Roles associated with the user."""
         roles = {}
 
+        # Cache the 'groups' queryset for the user
+        groups = prefetch_rule_sets(user)
+
         for ruleset in RULESET_CHOICES:
             role, _text = ruleset
 
             permissions = []
 
             for permission in RULESET_PERMISSIONS:
-                if check_user_role(user, role, permission):
+                if check_user_role(user, role, permission, groups=groups):
                     permissions.append(permission)
 
             if len(permissions) > 0:

src/frontend/src/tables/build/BuildLineTable.tsx

@@ -972,8 +972,10 @@ export default function BuildLineTable({
             ...params,
             build: build.pk,
             assembly_detail: false,
+            bom_item_detail: true,
             category_detail: true,
-            part_detail: true
+            part_detail: true,
+            allocations: true
           },
           tableActions: tableActions,
           tableFilters: tableFilters,

src/frontend/src/tables/build/BuildOutputTable.tsx

@@ -206,7 +206,9 @@ export default function BuildOutputTable({
         .get(apiUrl(ApiEndpoints.build_line_list), {
           params: {
             build: buildId,
-            tracked: true
+            tracked: true,
+            bom_item_detail: true,
+            allocations: true
           }
         })
         .then((response) => response.data);

src/frontend/src/tables/part/PartBuildAllocationsTable.tsx

@@ -165,7 +165,8 @@ export default function PartBuildAllocationsTable({
           project_code_detail: true,
           assembly_detail: true,
           build_detail: true,
-          order_outstanding: true
+          order_outstanding: true,
+          allocations: true
         },
         enableColumnSwitching: true,
         enableSearch: false,

src/frontend/src/tables/purchasing/PurchaseOrderLineItemTable.tsx

@@ -439,7 +439,8 @@ export function PurchaseOrderLineItemTable({
           params: {
             ...params,
             order: orderId,
-            part_detail: true
+            part_detail: true,
+            destination_detail: true
           },
           rowActions: rowActions,
           tableActions: tableActions,

src/frontend/tests/pages/pui_purchase_order.spec.ts

@@ -419,7 +419,8 @@ test('Purchase Orders - Receive Items', async ({ browser }) => {
     .getByRole('cell', { name: /Choose Location/ })
     .getByText('Room 101')
     .waitFor();
-  await page.getByText('Mechanical Lab').waitFor();
+
+  await page.getByText('Mechanical Lab').first().waitFor();
 
   await page.getByRole('button', { name: 'Cancel' }).click();