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".

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

Browser compatibility

Feature	Chrome	Firefox (Gecko)	Internet Explorer	Opera	Safari (WebKit)
Basic support	48.0	44.0 (44.0) [1]	10, partial	15	7.1
Available in workers	48.0	?	?	35	?

Feature	Android	Android Webview	Firefox Mobile (Gecko)	Firefox OS	IE Phone	Opera Mobile	Safari Mobile	Chrome for Android
Basic support	4.4	48.0	44.0 (44.0) [1]	1.0.1	10	22	No support	48.0
Available in workers	No support	48.0	?	?	?	35	?	48.0

[1] Was available since Firefox 27 behing the pref dom.indexedDB.experimental, off by default.

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