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.
Note: This feature is available in Web Workers.
Syntax
varrequest= ObjectStore.count(); varrequest= ObjectStore.count(query);
Parameters
- query Optional
- A key or
IDBKeyRangeobject 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.
Exceptions
This method may raise a DOMException of one of the following types:
| Exception | Description |
|---|---|
InvalidStateError |
This IDBObjectStore has been deleted. |
TransactionInactiveError |
This IDBObjectStore's transaction is inactive. |
DataError |
The specified key or key range is invalid. |
Example
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.
var transaction = db.transaction(['fThings'], 'readonly');
var objectStore = transaction.objectStore('fThings');
var countRequest = objectStore.count();
countRequest.onsuccess = function() {
console.log(countRequest.result);
}
Specification
| Specification | Status | Comment |
|---|---|---|
| Indexed Database API 2.0 The definition of 'count()' in that specification. |
Recommendation | |
| Indexed Database API Draft The definition of 'count()' in that specification. |
Recommendation |
Browser compatibility
The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
| Desktop | Mobile | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
count | Chrome
Full support
24
| Edge Full support 12 | Firefox
Full support
16
| IE Partial support 10 | Opera Full support 15 | Safari Full support 7 | WebView Android
Full support
Yes
| Chrome Android
Full support
25
| Firefox Android Full support 22 | Opera Android Full support 14 | Safari iOS Full support 8 | Samsung Internet Android
Full support
1.5
|
Legend
- Full support
- Full support
- Partial support
- Partial support
- Requires a vendor prefix or different name for use.
- Requires a vendor prefix or different name for use.
See also
- Using IndexedDB
- Starting transactions:
IDBDatabase - Using transactions:
IDBTransaction - Setting a range of keys:
IDBKeyRange - Retrieving and making changes to your data:
IDBObjectStore - Using cursors:
IDBCursor - Reference example: To-do Notifications (view example live.)
