MAGETWO-80188: [2.2.x] - Prevent change log entry when nothing has changed #4893

Author: dhorytskyi

app/etc/di.xml

@@ -1337,4 +1337,11 @@
             <argument name="defaultExceptionMessageFactory" xsi:type="object">Magento\Framework\Message\ExceptionMessageFactory</argument>
         </arguments>
     </type>
+    <type name="Magento\Framework\Mview\View\Subscription">
+        <arguments>
+            <argument name="ignoredUpdateColumns" xsi:type="array">
+                <item name="updated_at" xsi:type="string">updated_at</item>
+            </argument>
+        </arguments>
+    </type>
 </config>

lib/internal/Magento/Framework/Mview/View/Subscription.php

@@ -57,21 +57,31 @@ class Subscription implements SubscriptionInterface
      */
     protected $resource;
 
+    /**
+     * List of columns that can be updated in a subscribed table
+     * without creating a new change log entry
+     *
+     * @var array
+     */
+    private $ignoredUpdateColumns = [];
+
     /**
      * @param ResourceConnection $resource
      * @param \Magento\Framework\DB\Ddl\TriggerFactory $triggerFactory
      * @param \Magento\Framework\Mview\View\CollectionInterface $viewCollection
      * @param \Magento\Framework\Mview\ViewInterface $view
      * @param string $tableName
      * @param string $columnName
+     * @param array $ignoredUpdateColumns
      */
     public function __construct(
         ResourceConnection $resource,
         \Magento\Framework\DB\Ddl\TriggerFactory $triggerFactory,
         \Magento\Framework\Mview\View\CollectionInterface $viewCollection,
         \Magento\Framework\Mview\ViewInterface $view,
         $tableName,
-        $columnName
+        $columnName,
+        $ignoredUpdateColumns = []
     ) {
         $this->connection = $resource->getConnection();
         $this->triggerFactory = $triggerFactory;
@@ -80,6 +90,7 @@ public function __construct(
         $this->tableName = $tableName;
         $this->columnName = $columnName;
         $this->resource = $resource;
+        $this->ignoredUpdateColumns = $ignoredUpdateColumns;
     }
 
     /**
@@ -175,7 +186,7 @@ protected function getLinkedViews()
     }
 
     /**
-     * Build trigger statement for INSER, UPDATE, DELETE events
+     * Build trigger statement for INSERT, UPDATE, DELETE events
      *
      * @param string $event
      * @param \Magento\Framework\Mview\View\ChangelogInterface $changelog
@@ -185,25 +196,48 @@ protected function buildStatement($event, $changelog)
     {
         switch ($event) {
             case Trigger::EVENT_INSERT:
+                $trigger = "INSERT IGNORE INTO %s (%s) VALUES (NEW.%s);";
+                break;
+
             case Trigger::EVENT_UPDATE:
-                return sprintf(
-                    "INSERT IGNORE INTO %s (%s) VALUES (NEW.%s);",
-                    $this->connection->quoteIdentifier($this->resource->getTableName($changelog->getName())),
-                    $this->connection->quoteIdentifier($changelog->getColumnName()),
-                    $this->connection->quoteIdentifier($this->getColumnName())
-                );
+                $trigger = "INSERT IGNORE INTO %s (%s) VALUES (NEW.%s);";
+
+                if ($this->connection->isTableExists($this->getTableName())
+                    && $describe = $this->connection->describeTable($this->getTableName())
+                ) {
+                    $columnNames = array_column($describe, 'COLUMN_NAME');
+                    $columnNames = array_diff($columnNames, $this->ignoredUpdateColumns);
+                    if ($columnNames) {
+                        $columns = [];
+                        foreach ($columnNames as $columnName) {
+                            $columns[] = sprintf(
+                                'NEW.%1$s != OLD.%1$s',
+                                $this->connection->quoteIdentifier($columnName)
+                            );
+                        }
+                        $trigger = sprintf(
+                            "IF (%s) THEN %s END IF;",
+                            implode(' OR ', $columns),
+                            $trigger
+                        );
+                    }
+                }
+                break;
 
             case Trigger::EVENT_DELETE:
-                return sprintf(
-                    "INSERT IGNORE INTO %s (%s) VALUES (OLD.%s);",
-                    $this->connection->quoteIdentifier($this->resource->getTableName($changelog->getName())),
-                    $this->connection->quoteIdentifier($changelog->getColumnName()),
-                    $this->connection->quoteIdentifier($this->getColumnName())
-                );
+                $trigger = "INSERT IGNORE INTO %s (%s) VALUES (OLD.%s);";
+                break;
 
             default:
                 return '';
         }
+
+        return sprintf(
+            $trigger,
+            $this->connection->quoteIdentifier($this->resource->getTableName($changelog->getName())),
+            $this->connection->quoteIdentifier($changelog->getColumnName()),
+            $this->connection->quoteIdentifier($this->getColumnName())
+        );
     }
 
     /**