IDBObjectStore.clear()
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
.
Note: This feature is available in Web Workers
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 initialized.</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 request 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>';
};
};
Specifications
Specification |
---|
Indexed Database API 3.0 # ref-for-dom-idbobjectstore-clear③ |
Browser compatibility
BCD tables only load in the browser
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.)