The clear()
method of the IDBObjectStore
interface creates and immediately returns an IDBRequest
object, and clears this object store in a separate thread. This is for deleting all the current data out of an object store.
Clearing an object store consists of removing all records from the object store and removing all records in indexes that reference the object store. To remove only some of the records in a store, use IDBObjectStore.delete
passing a key or IDBKeyRange
.
Syntax
var request = objectStore.clear();
Returns
An IDBRequest
object on which subsequent events related to this operation are fired.
Exceptions
This method may raise a DOMException
of one of the following types:
Exception | Description |
---|---|
ReadOnlyError |
The transaction associated with this operation is in read-only mode. |
TransactionInactiveError |
This IDBObjectStore 's transaction is inactive. |
Example
In the following code snippet, we open a read/write transaction on our database and clear all the current data out of the object store using clear()
. 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; // Clear all the data form the object store clearData(); }; function clearData() { // open a read/write db transaction, ready for clearing the data var transaction = db.transaction(["toDoList"], "readwrite"); // report on the success of the transaction completing, when everything is done transaction.oncomplete = function(event) { note.innerHTML += '<li>Transaction completed.</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"); // Make a erequest to clear all the data out of the object store var objectStoreRequest = objectStore.clear(); objectStoreRequest.onsuccess = function(event) { // report the success of our request note.innerHTML += '<li>Request successful.</li>'; }; };
Specification
Specification | Status | Comment |
---|---|---|
Indexed Database API The definition of 'clear()' in that specification. |
Recommendation | |
Indexed Database API 2.0 The definition of 'clear()' 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.)