IDBKeyRange: only() static method

{{ APIRef("IndexedDB") }} {{AvailableInWorkers}}

The only() static method of the {{domxref("IDBKeyRange")}} interface creates a new key range containing a single value.

Syntax

IDBKeyRange.only(value)

Parameters

• value
  • : The value for the new key range.

Return value

{{domxref("IDBKeyRange")}}: The newly created key range.

Exceptions

• DataError {{domxref("DOMException")}}
  • : Thrown if the value parameter was not a valid key.

Examples

The following example illustrates how you'd use an only key range. Here we declare a keyRangeValue = IDBKeyRange.only("A"); — a range that only includes the value "A". We open a transaction (using {{domxref("IDBTransaction")}}) and an object store, and open a Cursor with {{domxref("IDBObjectStore.openCursor")}}, declaring keyRangeValue as its optional key range value. This means that the cursor will only retrieve the record with the key value "A".

[!NOTE] For a more complete example allowing you to experiment with key range, have a look at our IDBKeyRange repo (view the example live too.)

function displayData() {
  const keyRangeValue = IDBKeyRange.only("A");

  const transaction = db.transaction(["fThings"], "readonly");
  const objectStore = transaction.objectStore("fThings");

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

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

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also

• Using IndexedDB
• Starting transactions: {{domxref("IDBDatabase")}}
• Using transactions: {{domxref("IDBTransaction")}}
• Setting a range of keys: {{domxref("IDBKeyRange")}}
• Retrieving and making changes to your data: {{domxref("IDBObjectStore")}}
• Using cursors: {{domxref("IDBCursor")}}
• Reference example: To-do Notifications (View the example live).