IDBCursor: key property

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

Note: This feature is available in Web Workers.

The key read-only property of the IDBCursor interface returns the key for the record at the cursor's position. If the cursor is outside its range, this is set to undefined. The cursor's key can be any data type.

Value

A value of any type.

Exceptions

InvalidStateError DOMException

Thrown if the cursor is advancing or has finished.

Examples

In this simple fragment we create a transaction, retrieve an object store, then use a cursor to iterate through all the records in the object store. Within each iteration we log the key of the cursor to the console.

The cursor does not require us to select the data based on a key; we can just grab all of it. Also note that in each iteration of the loop, you can grab data from the current record under the cursor object using cursor.value.foo. For a complete working example, see our IDBCursor example (View the example live).

js
function displayData() {
  const transaction = db.transaction(["rushAlbumList"], "readonly");
  const objectStore = transaction.objectStore("rushAlbumList");

  objectStore.openCursor().onsuccess = (event) => {
    const cursor = event.target.result;
    if (cursor) {
      const listItem = document.createElement("li");
      listItem.textContent = `${cursor.value.albumTitle}, ${cursor.value.year}`;
      list.appendChild(listItem);

      console.log(cursor.key);
      cursor.continue();
    } else {
      console.log("Entries all displayed.");
    }
  };
}

Specifications

Specification
Indexed Database API 3.0
# ref-for-dom-idbcursor-key①

Browser compatibility

desktop mobile
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
key
Chrome – Full support
Chrome 23 (Release date: 2012-11-06)
footnote Full support
Edge – Full support
Edge 12 (Release date: 2015-07-29)
footnote Full support
Firefox – Full support
Firefox 10 (Release date: 2012-01-31)
footnote Full support
Opera – Full support
Opera 15 (Release date: 2013-07-02)
footnote Full support
Safari – Full support
Safari 8 (Release date: 2014-10-16)
footnote Full support
Chrome Android – Full support
Chrome Android 25 (Release date: 2013-02-27)
footnote Full support
Firefox for Android – Full support
Firefox for Android 22 (Release date: 2013-06-25)
footnote Full support
Opera Android – Full support
Opera Android 14 (Release date: 2013-05-21)
footnote Full support
Safari on iOS – Full support
Safari on iOS 8 (Release date: 2014-09-17)
footnote Full support
Samsung Internet – Full support
Samsung Internet 1.5 (Release date: 2013-09-25)
footnote Full support
WebView Android – Full support
WebView Android 4.4 (Release date: 2013-12-09)
footnote Full support
WebView on iOS – Full support
WebView on iOS 8 (Release date: 2014-09-17)
footnote Full support
Binary keys
Chrome – Full support
Chrome 58 (Release date: 2017-04-19)
footnote Full support
Edge – Full support
Edge 79 (Release date: 2020-01-15)
footnote Full support
Firefox – Full support
Firefox 51 (Release date: 2017-01-24)
footnote Full support
Opera – Full support
Opera 45 (Release date: 2017-05-10)
footnote Full support
Safari – Full support
Safari 10.1 (Release date: 2017-03-27)
footnote Full support
Chrome Android – Full support
Chrome Android 58 (Release date: 2017-04-25)
footnote Full support
Firefox for Android – Full support
Firefox for Android 51 (Release date: 2017-01-24)
footnote Full support
Opera Android – Full support
Opera Android 43 (Release date: 2017-09-27)
footnote Full support
Safari on iOS – Full support
Safari on iOS 10.3 (Release date: 2017-03-27)
footnote Full support
Samsung Internet – Full support
Samsung Internet 7 (Release date: 2018-03-16)
footnote Full support
WebView Android – Full support
WebView Android 58 (Release date: 2017-04-25)
footnote Full support
WebView on iOS – Full support
WebView on iOS 10.3 (Release date: 2017-03-27)
footnote Full support

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support

See also