eZ\Publish\Core\Persistence\Legacy\Content\FieldHandler::deleteFields PHP Method

    public function deleteFields($contentId, VersionInfo $versionInfo)
    {
        foreach ($this->contentGateway->getFieldIdsByType($contentId, $versionInfo->versionNo) as $fieldType => $ids) {
            $this->storageHandler->deleteFieldData($fieldType, $versionInfo, $ids);
        }
        $this->contentGateway->deleteFields($contentId, $versionInfo->versionNo);
    }

 /**
  * Deletes raw content data.
  *
  * @param int $contentId
  */
 public function removeRawContent($contentId)
 {
     $this->locationGateway->removeElementFromTrash($this->loadContentInfo($contentId)->mainLocationId);
     foreach ($this->listVersions($contentId) as $versionInfo) {
         $this->fieldHandler->deleteFields($contentId, $versionInfo);
     }
     // Must be called before deleteRelations()
     $this->contentGateway->removeReverseFieldRelations($contentId);
     $this->contentGateway->deleteRelations($contentId);
     $this->contentGateway->deleteVersions($contentId);
     $this->contentGateway->deleteNames($contentId);
     $this->contentGateway->deleteContent($contentId);
 }