IDBRequest.error
The error
property of the IDBRequest
interface returns the error in the event of an unsuccessful request.
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 to-do list object that has this title as it's 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. |
Editor's Draft |
Browser compatibility
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
---|---|---|---|---|---|
Basic support | 23webkit 24 |
10 moz 16.0 (16.0) |
10, partial | 15 | 7.1 |
Available in workers | (Yes) | 37.0 (37.0) | ? | (Yes) | ? |
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 | 8 |
Available in workers | (Yes) | 37.0 (37.0) | (Yes) | ? | (Yes) | ? |
See also
- Using IndexedDB
- Starting transactions:
IDBDatabase
- Using transactions:
IDBTransaction
- Setting a range of keys:
IDBKeyRange
- Retrieving and making changes to your data:
IDBObjectStore
- Using cursors:
IDBCursor
- Reference example: To-do Notifications (view example live.)
License
© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-us/docs/web/api/idbrequest/error