Web/API/IDBTransaction/error

The IDBTransaction.error property of the IDBTransaction interface returns one of several types of error when there is an unsuccessful transaction.

Note: This feature is available in Web Workers.

Syntax

var myError = transaction.error;

Value

A DOMError containing the relevant error. In Chrome 48+/Firefox 58+ this property returns a DOMException because DOMError has been removed from the DOM standard. The exact error is one of serveral possibilities. It can be a reference to the same error as the request object that raised it, or a transaction failure (for example QuotaExceededError or UnknownError).

This property is null if the transaction is not finished, is finished and successfully committed, or was aborted with the IDBTransaction.abort method.

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 ([[../../../../../../../mdn.github.io/to-do-notifications/index|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 the request (this does not mean the item
    // has been stored successfully in the DB - for that you need transaction.onsuccess)
    note.innerHTML += '<li>Request successful.</li>';
  };
};

Specification

Specification	Status	Comment
Indexed Database API 2.0The definition of 'error' in that specification.	Recommendation
Indexed Database API DraftThe definition of 'error' in that specification.	Recommendation

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`error`	Chrome Full support 24 Full support 24 No support 23 — 57 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	Edge Full support 12	Firefox Full support 16 Full support 16 No support 10 — 16 Prefixed' Prefixed' Implemented with the vendor prefix: moz	IE Partial support 10	Opera Full support 15	Safari Full support 7	WebView Android Full support Yes Full support Yes No support ? — 57 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	Chrome Android Full support 25 Full support 25 No support 25 — 57 Prefixed' Prefixed' Implemented with the vendor prefix: webkit	Firefox Android Full support 22	Opera Android Full support 14	Safari iOS Full support 8	Samsung Internet Android Full support 1.5 Full support 1.5 No support 1.5 — 7.0 Prefixed' Prefixed' Implemented with the vendor prefix: webkit
`DOMException` value instead of `DOMError`	Chrome Full support 48	Edge Full support ≤18	Firefox Full support 58	IE No support No	Opera Full support Yes	Safari No support No	WebView Android Full support 48	Chrome Android Full support 48	Firefox Android Full support 58	Opera Android Full support Yes	Safari iOS No support No	Samsung Internet Android Full support 5.0

Legend

Full support: Full support
Partial support: Partial support
No support: No support
Requires a vendor prefix or different name for use.': Requires a vendor prefix or different name for use.