The openKeyCursor()
method of the IDBObjectStore
interface returns an IDBRequest
object whose result will be set to an IDBCursor
that can be used to iterate through matching results. Used for iterating through the keys of an object store with a cursor.
To determine if the add operation has completed successfully, listen for the results’s success
event.
Syntax
var request = objectStore.openKeyCursor(); var request = objectStore.openKeyCursor(query); var request = objectStore.openKeyCursor(query, direction);
Parameters
- query Optional
- The key range to be queried. If a single valid key is passed, this will default to a range containing only that key. If nothing is passed, this will default to a key range that selects all the records in this object store.
- direction Optional
- An
IDBCursorDirection
telling the cursor what direction to travel. Valid values are"next"
,"nextunique"
,"prev"
, and"prevunique"
. The default is"next"
.
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 or IDBIndex 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 use a cursor to iterate through all the records in the object store:
var transaction = db.transaction("name", "readonly"); var objectStore = transaction.objectStore("name"); var request = objectStore.openKeyCursor(); request.onsuccess = function(event) { var cursor = event.target.result; if(cursor) { // cursor.key contains the key of the current record being iterated through // note that there is no cursor.value, unlike for openCursor // this is where you'd do something with the result cursor.continue(); } else { // no more results } };
Specifications
Specification | Status | Comment |
---|---|---|
Unknown The definition of 'openKeyCursor()' in that specification. |
Recommendation | |
Indexed Database API 2.0 The definition of 'openKeyCursor()' in that specification. |
Editor's Draft |
Browser compatibility
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
---|---|---|---|---|---|
Basic support | 48 | 44.0 (44.0) [1] | 10, partial | 15 | 7.1 |
Available in workers | 48 | ? | ? | 35 | ? |
Indexed Database 2.0 | 58 | ? | ? | 45 | ? |
Feature | Android Webview | Chrome for Android | Firefox Mobile (Gecko) | Firefox OS | IE Phone | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|---|
Basic support | 48 | 48 | 44.0 (44.0) [1] | 1.0.1 | 10 | 22 | No support |
Available in workers | 48 | 48 | ? | ? | ? | 35 | ? |
Indexed Database 2.0 | 58 | 58 | ? | ? | ? | 45 | ? |
[1] Was available since Firefox 27 behing the pref dom.indexedDB.experimental
, off by default.
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.)