IDBTransaction.error

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This article is in need of a technical review.

The error property of the IDBTransaction interface returns a description of the error thrown in the event of an unsuccessful transaction.

This is null if the transaction is not finished, is finished and successfully committed, or was aborted with the IDBTransaction.abort method. Otherwise, it returns the same DOMError as the request object that caused the transaction to be aborted due to a failed request, or a DOMError for the transaction failure if it is not due to a failed request (for example QuotaExceededError or UnknownError).

Syntax

var myError = transaction.error;

Value

A DOMError.

Example

In the following code snippet, we open a read/write transaction on our database and add some data to an object store. Note also the functions attached to transaction event handlers to report on the outcome of the transaction opening in the event of success or failure. Note the transaction.onerror = function(event) { }; block, making use of transaction.error to help in reporting what went wrong when the transaction was unsuccessful. For a full working example, see our To-do Notifications app (view example live.)

// Let us open our database
var DBOpenRequest = window.indexedDB.open("toDoList", 4);

DBOpenRequest.onsuccess = function(event) {
  note.innerHTML += '<li>Database initialised.</li>';
    
  // store the result of opening the database in the db variable. This is used a lot below
  db = DBOpenRequest.result;
    
  // Run the addData() function to add the data to the database
  addData();
};

function addData() {
  // Create a new object ready for being inserted into the IDB
  var newItem = [ { taskTitle: "Walk dog", hours: 19, minutes: 30, day: 24, month: "December", year: 2013, notified: "no" } ];

  // open a read/write db transaction, ready for adding the data
  var transaction = db.transaction(["toDoList"], "readwrite");

  // report on the success of opening the transaction
  transaction.oncomplete = function(event) {
    note.innerHTML += '<li>Transaction completed: database modification finished.</li>';
  };


  transaction.onerror = function(event) {
    note.innerHTML += '<li>Transaction not opened due to error: ' + transaction.error + '</li>';
  };

  // create an object store on the transaction
  var objectStore = transaction.objectStore("toDoList");

  // add our newItem object to the object store
  var objectStoreRequest = objectStore.add(newItem[0]);

  objectStoreRequest.onsuccess = function(event) {
    // report the success of our new item going into the database
    note.innerHTML += '<li>New item added to database.</li>';
  };
};

Specification

Specification Status Comment
Indexed Database API
The definition of 'IDBTransaction' in that specification.
Candidate Recommendation  

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 23webkit
24
16.0 (16.0) 10, partial 15 7.1
Feature Android Firefox Mobile (Gecko) Firefox OS IE Phone Opera Mobile Safari Mobile
Basic support 4.4 22.0 (22.0) 1.0.1 10 22 Not supported

See also

Document Tags and Contributors

Contributors to this page: fscholz, teoli, chrisdavidmills
Last updated by: fscholz,