IDBCursor: key property

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.

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

BCD tables only load in the browser

See also