The openCursor() method of the IDBObjectStore interface returns an IDBRequest object, and, in a separate thread, returns a new IDBCursorWithValue object. Used for iterating through an object store with a cursor.
To determine if the add operation has completed successfully, listen for the results’s success event.
Note: This feature is available in Web Workers.
Syntax
var request = ObjectStore.openCursor(); var request = ObjectStore.openCursor(query); var request = ObjectStore.openCursor(query, direction);
Parameters
- query Optional
- A key or
IDBKeyRangeto 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
IDBCursorDirectiontelling 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.openCursor();
request.onsuccess = function(event) {
var cursor = event.target.result;
if(cursor) {
// cursor.value contains the current record being iterated through
// this is where you'd do something with the result
cursor.continue();
} else {
// no more results
}
};
Specification
| Specification | Status | Comment |
|---|---|---|
| Indexed Database API The definition of 'openCursor()' in that specification. |
Recommendation | |
| Indexed Database API 2.0 The definition of 'openCursor()' in that specification. |
Editor's Draft |
Browser compatibility
| Feature | Chrome | Edge | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
|---|---|---|---|---|---|---|
| Basic support | 23webkit 24 (unprefixed) |
(Yes) | 10 moz 16.0 (16.0) |
10, partial | 15 | 7.1 |
| Available in workers | (Yes) | ? | 37.0 (37.0) | ? | (Yes) | ? |
| Indexed Database 2.0 | 58 | ? | ? | ? | 45 | ? |
| Feature | Android Webview | Chrome for Android | Edge | Firefox Mobile (Gecko) | Firefox OS | IE Phone | Opera Mobile | Safari Mobile |
|---|---|---|---|---|---|---|---|---|
| Basic support | (Yes) | (Yes) | (Yes) | 22.0 (22.0) | 1.0.1 | 10 | 22 | 8 |
| Available in workers | (Yes) | (Yes) | ? | 37.0 (37.0) | (Yes) | ? | (Yes) | ? |
| Indexed Database 2.0 | 58 | 58 | ? | ? | ? | ? | 45 | ? |
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.)