IDBObjectStore.delete() - Web APIs 编辑

The delete() method of the IDBObjectStore interface returns an IDBRequest object, and, in a separate thread, deletes the specified record or records.

Either a key or an IDBKeyRange can be passed, allowing one or multiple records to be deleted from a store. To delete all records in a store, use  IDBObjectStore.clear.

Bear in mind that if you are using a IDBCursor, you can use the IDBCursor.delete() method to more efficiently delete the current record — without having to explicitly look up the record's key.

Note:

Syntax

var request = objectStore.delete(Key);

var request = objectStore.delete(KeyRange);

Parameters

Key

The key of the record to be deleted, or an IDBKeyRange to delete all records with keys in range.

Return value

An IDBRequest object on which subsequent events related to this operation are fired. The request.result attribute is set to undefined.

Exceptions

This method may raise a DOMException of the following types:

Example

In the following code snippet, we open a read/write transaction on our database and delete one specific record out of our object store using delete() — a sample record with the key "Walk dog". 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;

  // Run the deleteData() function to delete a record from the database
  deleteData();
};

function deleteData() {
  // open a read/write db transaction, ready for deleting 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 delete the specified record out of the object store
  var objectStoreRequest = objectStore.delete("Walk dog");

  objectStoreRequest.onsuccess = function(event) {
    // report the success of our request
    note.innerHTML += '<li>Request successful.</li>';
  };
};

Specifications

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.)