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
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 2.0 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.)