Web/API/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+/Firefox 58+ 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 ([[../../../../../../../mdn.github.io/to-do-notifications/index|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 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.