Fixed n+1 query bug when eager-loading elements on nested entries

brandonkelly · brandonkelly · commit 8cb3e3612629 · 2025-01-24T18:29:14.000-08:00
- Element::eagerLoadingMap() calls EagerLoadingFieldInterface::getFieldLayout() for each source element
- Entry::getFieldLayout() calls $this-&gt;getType()
- Entry::getType() calls $this-&gt;getAvailableEntryTypes()
- Entry::getAvailableEntryTypes() calls $this-&gt;getField()
- NestedElementTrait::getField() calls $this-&gt;getOwner()
- NestedElementTrait::getOwner() (or getPrimaryOwner()) executes queries to fetch the owner type and then the owner.

Solution is to have getOwner() and getPrimaryOwner() eager-load the owner element onto all of the nested elements that were queried together, rather than just the current one. So the data is already in place for each of the following source elements.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -7,6 +7,7 @@
 - Fixed a bug where Color fields’ custom color inputs were including presets based on the color palette.
 - Fixed a bug where nested Matrix entries weren’t getting assigned a post date if they were created while saving the owner element with a custom validation scenario. ([#16504](https://github.com/craftcms/cms/pull/16504))
 - Fixed a bug where plugin settings pages weren’t displaying a read-only notice and had Save buttons, when `allowAdminChanges` was `false`. ([#16509](https://github.com/craftcms/cms/pull/16509))
+- Fixed a bug where eager-loading elements on nested entries resulted in a large number of database queries.
 
 ## 5.6.1 - 2025-01-22
 
diff --git a/src/base/NestedElementTrait.php b/src/base/NestedElementTrait.php
@@ -164,25 +164,31 @@ public function getPrimaryOwner(): ?ElementInterface
                 return null;
             }
 
-            $ownerType = $this->ownerType();
-            if (!$ownerType) {
-                return null;
-            }
+            if (isset($this->elementQueryResult)) {
+                // Eager-load the primary owner for each of the elements in the result,
+                // as we're probably going to end up needing them too
+                Craft::$app->getElements()->eagerLoadElements($this::class, $this->elementQueryResult, ['primaryOwner']);
+            } else {
+                $ownerType = $this->ownerType();
+                if (!$ownerType) {
+                    return null;
+                }
 
-            $this->_primaryOwner = $ownerType::find()
-                ->id($primaryOwnerId)
-                ->site('*')
-                ->preferSites([$this->siteId])
-                ->unique()
-                ->status(null)
-                ->drafts(null)
-                ->provisionalDrafts(null)
-                ->revisions(null)
-                ->trashed(null)
-                ->one() ?? false;
-
-            if (!$this->_primaryOwner) {
-                throw new InvalidConfigException("Invalid owner ID: $primaryOwnerId");
+                $this->_primaryOwner = $ownerType::find()
+                    ->id($primaryOwnerId)
+                    ->site('*')
+                    ->preferSites([$this->siteId])
+                    ->unique()
+                    ->status(null)
+                    ->drafts(null)
+                    ->provisionalDrafts(null)
+                    ->revisions(null)
+                    ->trashed(null)
+                    ->one() ?? false;
+
+                if (!$this->_primaryOwner) {
+                    throw new InvalidConfigException("Invalid owner ID: $primaryOwnerId");
+                }
             }
         }
 
@@ -230,25 +236,31 @@ public function getOwner(): ?ElementInterface
                 return $this->getPrimaryOwner();
             }
 
-            $ownerType = $this->ownerType();
-            if (!$ownerType) {
-                return null;
-            }
+            if (isset($this->elementQueryResult)) {
+                // Eager-load the owner for each of the elements in the result,
+                // as we're probably going to end up needing them too
+                Craft::$app->getElements()->eagerLoadElements($this::class, $this->elementQueryResult, ['owner']);
+            } else {
+                $ownerType = $this->ownerType();
+                if (!$ownerType) {
+                    return null;
+                }
 
-            $this->_owner = $ownerType::find()
-                ->id($ownerId)
-                ->site('*')
-                ->preferSites([$this->siteId])
-                ->unique()
-                ->status(null)
-                ->drafts(null)
-                ->provisionalDrafts(null)
-                ->revisions(null)
-                ->trashed(null)
-                ->one() ?? false;
-
-            if (!$this->_owner) {
-                throw new InvalidConfigException("Invalid owner ID: $ownerId");
+                $this->_owner = $ownerType::find()
+                    ->id($ownerId)
+                    ->site('*')
+                    ->preferSites([$this->siteId])
+                    ->unique()
+                    ->status(null)
+                    ->drafts(null)
+                    ->provisionalDrafts(null)
+                    ->revisions(null)
+                    ->trashed(null)
+                    ->one() ?? false;
+
+                if (!$this->_owner) {
+                    throw new InvalidConfigException("Invalid owner ID: $ownerId");
+                }
             }
         }
 
