error
Summary
Null if the transaction is not finished, is finished and successfully committed, or was aborted with the abort() function. Returns the same DOMError as the request object which caused the transaction to be aborted due to a failed request, or a DOMError for the transaction failure not due to a failed request (such as QuotaExceededError or UnknownError).
Property of apis/indexeddb/IDBTransactionapis/indexeddb/IDBTransaction
Syntax
Note: This property is read-only.
var result = element.error;
Return Value
Returns an object of type DOMErrorDOMError
Attributions
Mozilla Developer Network : Article