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
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).
// 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
- 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 the example live).