The IDBTransaction.error
property of the IDBTransaction
interface returns one of several types of error when there is an unsuccessful transaction.
Syntax
var myError = transaction.error;
Value
An object containing the relevant error. In Indexed Database, version 1 this is a DOMError
in version 2 it is a DOMException
as well as Chrome 48 and later. 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 (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 The definition of 'error' in that specification. |
Recommendation | |
Indexed Database API 2.0 The definition of 'error' in that specification. |
Editor's Draft |
Browser compatibility
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 | ? |
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.)