web api instance method

IDBObjectStore: count() method

Available in workers

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

Syntax

count()
count(query)

Parameters

query Optional
- : A key or IDBKeyRange object that specifies a range of records you want to count.

Return value

An IDBRequest object on which subsequent events related to this operation are fired.

If the operation is successful, the value of the request’s result property is the number of records that match the given query.

Exceptions

This method may raise a DOMException of one of the following types:

InvalidStateError DOMException
- : Thrown if this IDBObjectStore has been deleted.
TransactionInactiveError DOMException
- : Thrown if this IDBObjectStore’s transaction is inactive.
DataError 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

SpecificationsStandards references are available on the canonical MDN page.

Browser compatibility

Browser compatibilityCompatibility data is available on the canonical MDN page.