IDBObjectStore: count() method

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

The count() method of the {{domxref("IDBObjectStore")}} interface returns an {{domxref("IDBRequest")}} object, and, in a separate thread, returns the total number of records that match the provided key or {{domxref("IDBKeyRange")}}. If no arguments are provided, it returns the total number of records in the store.

Syntax

count()
count(query)

Parameters

• query {{optional_inline}}
  • : A key or {{domxref("IDBKeyRange")}} object that specifies a range of records you want to count.

Return value

An {{domxref("IDBRequest")}} object on which subsequent events related to this operation are fired.

If the operation is successful, the value of the request's {{domxref("IDBRequest.result", "result")}} property is the number of records that match the given query.

Exceptions

This method may raise a {{domxref("DOMException")}} of one of the following types:

• InvalidStateError {{domxref("DOMException")}}
  • : Thrown if this {{domxref("IDBObjectStore")}} has been deleted.
• TransactionInactiveError {{domxref("DOMException")}}
  • : Thrown if this {{domxref("IDBObjectStore")}}'s transaction is inactive.
• DataError {{domxref("DOMException")}}
  • : Thrown if the specified key or key range is invalid.

Examples

In this simple fragment we create a transaction, retrieve an object store, then count the number of records in the store using count() — when the success handler fires, we log the count value (an integer) to the console.

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

const countRequest = objectStore.count();
countRequest.onsuccess = () => {
  console.log(countRequest.result);
};

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).