IDBObjectStore.openKeyCursor()

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(optionalKeyRange, optionalDirection);

Parameters

optionalKeyRange
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.
optionalDirection
An IDBCursorDirection telling the cursor what direction to travel. Defaults to "next".

Returns

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
  }
};

Specification

Specification Status Comment
Indexed Database API (Second Edition)
The definition of 'openKeyCursor' in that specification.
Editor's Draft  

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 48.0 27.0 (27.0) 10, partial 15 7.1
           
Feature Android Android Webview Firefox Mobile (Gecko) Firefox OS IE Phone Opera Mobile Safari Mobile Chrome for Android
Basic support 4.4 ? 27.0 (27.0) 1.0.1 10 22 No support ?
Unprefixed No support 48.0           48.0

See also

License

© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-us/docs/web/api/idbobjectstore/openkeycursor