IDBRequest.error

The error read-only property of the IDBRequest interface returns the error in the event of an unsuccessful request.

Note: This feature is available in Web Workers.

Syntax

var myError = request.error;

Value

A DOMError containing the relevant error. In Chrome 48 and later this property returns a DOMException because DOMError has been removed from the DOM standard. The following error codes are returned under certain conditions:

Error	Explanation
`AbortError`	If you abort the transaction, then all requests still in progress receive this error.
`ConstraintError`	If you insert data that doesn't conform to a constraint. It's an exception type for creating stores and indexes. You get this error, for example, if you try to add a new key that already exists in the record.
`QuotaExceededError`	If you run out of disk quota and the user declined to grant you more space.
`UnknownError`	If the operation failed for reasons unrelated to the database itself. A failure due to disk IO errors is such an example.
`NoError`	If the request succeeds.
`VersionError`	If you try to open a database with a version lower than the one it already has.

In addition to the error codes sent to the IDBRequest object, asynchronous operations can also raise exceptions. The list describes problems that could occur when the request is being executed, but you might also encounter other problems when the request is being made. For example, if the the request failed and the result is not available, the InvalidStateError exception is thrown.

Example

The following example requests a given record title, onsuccess gets the associated record from the IDBObjectStore (made available as objectStoreTitleRequest.result), updates one property of the record, and then puts the updated record back into the object store. Also included at the bottom is an onerror function that reports what the error was if the request fails. For a full working example, see our To-do Notifications app (view example live.)

var title = "Walk dog";
// Open up a transaction as usual
var objectStore = db.transaction(['toDoList'], "readwrite").objectStore('toDoList');
// Get the do-do list with the specified title
var objectStoreTitleRequest = objectStore.get(title);
objectStoreTitleRequest.onsuccess = function() {
  // Grab the data object returned as the result
  var data = objectStoreTitleRequest.result;
  // Update the notified value in the object to "yes"
  data.notified = "yes";
  // Create another request that inserts the item
  // back into the database
  var updateTitleRequest = objectStore.put(data);
  // When this new request succeeds, run the displayData()
  // function again to update the display
  updateTitleRequest.onsuccess = function() {
    displayData();
  };
};
objectStoreTitleRequest.onerror = function() {
  // If an error occurs with the request, log what it is
  console.log("There has been an error with retrieving your data: " + objectStoreTitleRequest.error);
};

Specifications

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

Feature	Chrome	Edge	Firefox (Gecko)	Internet Explorer	Opera	Safari (WebKit)
Basic support	23webkit 24 (unprefixed)	(Yes)	10 moz 16.0 (16.0)	10, partial	15	7.1
Available in workers	(Yes)	?	37.0 (37.0)	?	(Yes)	?
Indexed Database 2.0	58	?	?	?	45	?

Feature	Android Webview	Chrome for Android	Edge	Firefox Mobile (Gecko)	Firefox OS	IE Phone	Opera Mobile	Safari Mobile
Basic support	(Yes)	(Yes)	(Yes)	22.0 (22.0)	1.0.1	10	22	8
Available in workers	(Yes)	(Yes)	?	37.0 (37.0)	(Yes)	?	(Yes)	?
Indexed Database 2.0	58	58	?	?	?	?	45	?