public function getRelationsByChild($childrenIds)
    {
        $metadata      = $this->getEntityMetaData(\Magento\Catalog\Api\Data\ProductInterface::class);
        $entityTable   = $this->getTable($metadata->getEntityTable());
        $relationTable = $this->getTable('catalog_product_relation');
        $joinCondition = sprintf('relation.parent_id = entity.%s', $metadata->getLinkField());

        $select = $this->getConnection()->select()
            ->from(['relation' => $relationTable], [])
            ->join(['entity' => $entityTable], $joinCondition, [$metadata->getIdentifierField()])
            ->where('child_id IN(?)', array_map('intval', $childrenIds));

        return $this->getConnection()->fetchCol($select);
    }