ACP2E-766: Error during Category import 'Integrity constraint violation: 1062 Duplicate entry'

Author: Oleksandr Iegorov

app/code/Magento/CatalogImportExport/Model/Import/Product/Validator.php

@@ -310,7 +310,11 @@ protected function isValidAttributes()
         if ($entityTypeModel) {
             foreach ($this->_rowData as $attrCode => $attrValue) {
                 $attrParams = $entityTypeModel->retrieveAttributeFromCache($attrCode);
-                if ($attrParams) {
+                if ($attrCode === Product::COL_CATEGORY) {
+                    if (!$this->isCategoriesValid($attrValue)) {
+                        return false;
+                    }
+                } elseif ($attrParams) {
                     $this->isAttributeValid($attrCode, $attrParams, $this->_rowData);
                 }
             }
@@ -352,6 +356,30 @@ public function getRowScope(array $rowData)
         return Product::SCOPE_STORE;
     }
 
+    /**
+     * Validate category names
+     *
+     * @param string $value
+     * @return bool
+     */
+    private function isCategoriesValid(string $value) : bool
+    {
+        $result = true;
+        if ($value) {
+            $values = explode($this->context->getMultipleValueSeparator(), $value);
+            foreach ($values as $categoryName) {
+                if ($result === true) {
+                    $result = $this->string->strlen($categoryName) < Product::DB_MAX_VARCHAR_LENGTH;
+                }
+            }
+        }
+        if ($result === false) {
+            $this->_addMessages([RowValidatorInterface::ERROR_EXCEEDED_MAX_LENGTH]);
+            $this->setInvalidAttribute(Product::COL_CATEGORY);
+        }
+        return $result;
+    }
+
     /**
      * Init
      *