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
var request = ObjectStore.count(); var request = ObjectStore.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.
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 2.0The definition of 'count()' in that specification. | Recommendation | |
Indexed Database API DraftThe 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.
Update compatibility data on GitHub
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
count
|
Chrome Full support 24 Full support 24 No support 23 — 57 Prefixed' Implemented with the vendor prefix: webkit |
Edge
Full support 12 |
Firefox Full support 16 Full support 16 No support 10 — 16 Prefixed' Implemented with the vendor prefix: moz |
IE
Partial support 10 |
Opera
Full support 15 |
Safari
Full support 7 |
WebView Android Full support Yes Full support Yes No support ? — 57 Prefixed' Implemented with the vendor prefix: webkit |
Chrome Android Full support 25 Full support 25 No support 25 — 57 Prefixed' Implemented with the vendor prefix: webkit |
Firefox Android
Full support 22 |
Opera Android
Full support 14 |
Safari iOS
Full support 8 |
Samsung Internet Android Full support 1.5 Full support 1.5 No support 1.5 — 7.0 Prefixed' Implemented with the vendor prefix: webkit |
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 ([[../../../../../../../mdn.github.io/to-do-notifications/index|view example live]].)
IDBObjectStore.count() by Mozilla Contributors is licensed under CC-BY-SA 2.5.