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 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 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>';
  };
};

Specification

Specification Status Comment
Indexed Database API 2.0
The definition of 'clear()' in that specification.
Recommendation
Indexed Database API Draft
The definition of 'clear()' in that specification.
Recommendation

Browser compatibility

DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
clearChrome Full support 24
Full support 24
No support 23 — 57
Prefixed
Prefixed Implemented with the vendor prefix: webkit
Edge Full support 12Firefox Full support 16
Full support 16
No support 10 — 16
Prefixed
Prefixed Implemented with the vendor prefix: moz
IE Partial support 10Opera Full support 15Safari Full support 7WebView Android Full support Yes
Full support Yes
No support ? — 57
Prefixed
Prefixed Implemented with the vendor prefix: webkit
Chrome Android Full support 25
Full support 25
No support 25 — 57
Prefixed
Prefixed Implemented with the vendor prefix: webkit
Firefox Android Full support 22Opera Android Full support 14Safari iOS Full support 8Samsung Internet Android Full support 1.5
Full support 1.5
No support 1.5 — 7.0
Prefixed
Prefixed Implemented with the vendor prefix: webkit

Legend

Full support
Full support
Partial support
Partial support
Requires a vendor prefix or different name for use.
Requires a vendor prefix or different name for use.

See also