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
.
An IDBRequest
object on which subsequent events related to this operation are fired.
This method may raise a DOMException
of one of the following types:
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.)
var DBOpenRequest = window.indexedDB.open("toDoList", 4);
DBOpenRequest.onsuccess = function(event) {
note.innerHTML += '<li>Database initialized.</li>';
db = DBOpenRequest.result;
clearData();
};
function clearData() {
var transaction = db.transaction(["toDoList"], "readwrite");
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>';
};
var objectStore = transaction.objectStore("toDoList");
var objectStoreRequest = objectStore.clear();
objectStoreRequest.onsuccess = function(event) {
note.innerHTML += '<li>Request successful.</li>';
};
};