IDBObjectStore: clear() method

Note: This feature is available in Web Workers.

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

js
clear()

Parameters

None.

Return value

An IDBRequest object on which subsequent events related to this operation are fired.

If the operation is successful, the value of the request's result property is undefined.

Exceptions

ReadOnlyError DOMException

Thrown if the transaction associated with this operation is in read-only mode.

TransactionInactiveError DOMException

Thrown if this IDBObjectStore's transaction is inactive.

Examples

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).

js
// Let us open our database
const DBOpenRequest = window.indexedDB.open("toDoList", 4);

DBOpenRequest.onsuccess = (event) => {
  note.appendChild(document.createElement("li")).textContent =
    "Database initialized.";

  // store the result of opening the database in the db variable.
  // This is used a lot below
  db = DBOpenRequest.result;

  // Clear all the data from the object store
  clearData();
};

function clearData() {
  // open a read/write db transaction, ready for clearing the data
  const transaction = db.transaction(["toDoList"], "readwrite");

  // report on the success of the transaction completing, when everything is done
  transaction.oncomplete = (event) => {
    note.appendChild(document.createElement("li")).textContent =
      "Transaction completed.";
  };

  transaction.onerror = (event) => {
    note.appendChild(document.createElement("li")).textContent =
      `Transaction not opened due to error: ${transaction.error}`;
  };

  // create an object store on the transaction
  const objectStore = transaction.objectStore("toDoList");

  // Make a request to clear all the data out of the object store
  const objectStoreRequest = objectStore.clear();

  objectStoreRequest.onsuccess = (event) => {
    // report the success of our request
    note.appendChild(document.createElement("li")).textContent =
      "Request successful.";
  };
}

Specifications

Specification
Indexed Database API 3.0
# ref-for-dom-idbobjectstore-clear③

Browser compatibility

BCD tables only load in the browser

See also