The IDBCursor interface of the IndexedDB API represents a cursor for traversing or iterating over multiple records in a database.

The cursor has a source that indicates which index or object store it is iterating over. It has a position within the range, and moves in a direction that is increasing or decreasing in the order of record keys. The cursor enables an application to asynchronously process all the records in the cursor's range.

You can have an unlimited number of cursors at the same time. You always get the same IDBCursor object representing a given cursor. Operations are performed on the underlying index or object store.

Note: This feature is available in Web Workers.

Properties

IDBCursor.source Read only
Returns the IDBObjectStore or IDBIndex that the cursor is iterating. This function never returns null or throws an exception, even if the cursor is currently being iterated, has iterated past its end, or its transaction is not active.
IDBCursor.direction Read only
Returns the direction of traversal of the cursor. See Constants for possible values.
IDBCursor.key Read only
Returns the key for the record at the cursor's position. If the cursor is outside its range, this is set to undefined. The cursor's key can be any data type.
IDBCursor.value Read only
Returns the value for the record at the cursor's position. The cursor's value can be any data type.
IDBCursor.primaryKey Read only
Returns the cursor's current effective primary key. If the cursor is currently being iterated or has iterated outside its range, this is set to undefined. The cursor's primary key can be any data type.

Methods

IDBCursor.advance()
Sets the number times a cursor should move its position forward.
IDBCursor.continue()
Advances the cursor to the next position along its direction, to the item whose key matches the optional key parameter.
IDBCursor.continuePrimaryKey()
Sets the cursor to the given index key and primary key given as arguments.
IDBCursor.delete()
Returns an IDBRequest object, and, in a separate thread, deletes the record at the cursor's position, without changing the cursor's position. This can be used to delete specific records.
IDBCursor.update()
Returns an IDBRequest object, and, in a separate thread, updates the value at the current position of the cursor in the object store. This can be used to update specific records.

Constants

Deprecated since Gecko 13 (Firefox 13 / Thunderbird 13 / SeaMonkey 2.10)
This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

These constants are no longer available — they were removed in Gecko 25. You should use the string constants directly instead. (bug 891944)

  • NEXT : "next" : The cursor shows all records, including duplicates. It starts at the lower bound of the key range and moves upwards (monotonically increasing in the order of keys).
  • NEXTUNIQUE : "nextunique" : The cursor shows all records, excluding duplicates. If multiple records exist with the same key, only the first one iterated is retrieved. It starts at the lower bound of the key range and moves upwards.
  • PREV : "prev" : The cursor shows all records, including duplicates. It starts at the upper bound of the key range and moves downwards (monotonically decreasing in the order of keys).
  • PREVUNIQUE : "prevunique" : The cursor shows all records, excluding duplicates. If multiple records exist with the same key, only the first one iterated is retrieved. It starts at the upper bound of the key range and moves downwards.

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. The cursor does not require us to select the data based on a key; we can just grab all of it. Also note that in each iteration of the loop, you can grab data from the current record under the cursor object using cursor.value.foo. For a complete working example, see our IDBCursor example (view example live.)

function displayData() {
  var transaction = db.transaction(['rushAlbumList'], "readonly");
  var objectStore = transaction.objectStore('rushAlbumList');

  objectStore.openCursor().onsuccess = function(event) {
    var cursor = event.target.result;
    if(cursor) {
      var listItem = document.createElement('li');
      listItem.innerHTML = cursor.value.albumTitle + ', ' + cursor.value.year;
      list.appendChild(listItem);  

      cursor.continue();
    } else {
      console.log('Entries all displayed.');
    }
  };
}

Specifications

Specification Status Comment
Indexed Database API
The definition of 'cursor' in that specification.
Recommendation Initial definition
Indexed Database API 2.0
The definition of 'cursor' in that specification.
Recommendation Added continuePrimaryKey() and support for binary keys.

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
Basic supportChrome Full support 24
Full support 24
No support 23 — 57
Prefixed
Prefixed Implemented with the vendor prefix: webkit
Edge Full support YesFirefox Full support 16
Full support 16
No support 10 — 16
Prefixed
Prefixed Implemented with the vendor prefix: moz
IE Full support 10
Notes
Full support 10
Notes
Notes partial
Opera Full support 44
Full support 44
No support 15 — 44
Prefixed
Prefixed Implemented with the vendor prefix: webkit
Safari Full support 7WebView Android Full support Yes
Full support Yes
No support ? — 57
Prefixed
Prefixed Implemented with the vendor prefix: webkit
Chrome Android Full support 25
Full support 25
No support 25 — 57
Prefixed
Prefixed Implemented with the vendor prefix: webkit
Edge Mobile Full support YesFirefox Android Full support 22Opera Android Full support 22
Full support 22
No support 22 — 44
Prefixed
Prefixed Implemented with the vendor prefix: webkit
Safari iOS Full support 8Samsung Internet Android Full support Yes
Full support Yes
No support ? — 7.0
Prefixed
Prefixed Implemented with the vendor prefix: webkit
Available in workersChrome Full support 24
Full support 24
No support 23 — 57
Prefixed
Prefixed Implemented with the vendor prefix: webkit
Edge Full support YesFirefox Full support 37IE ? Opera Full support 44
Full support 44
No support 15 — 44
Prefixed
Prefixed Implemented with the vendor prefix: webkit
Safari Full support 7WebView Android Full support Yes
Full support Yes
No support ? — 57
Prefixed
Prefixed Implemented with the vendor prefix: webkit
Chrome Android Full support 25
Full support 25
No support 25 — 57
Prefixed
Prefixed Implemented with the vendor prefix: webkit
Edge Mobile Full support YesFirefox Android Full support 37Opera Android Full support Yes
Full support Yes
No support 22 — 44
Prefixed
Prefixed Implemented with the vendor prefix: webkit
Safari iOS ? Samsung Internet Android Full support Yes
Full support Yes
No support ? — 7.0
Prefixed
Prefixed Implemented with the vendor prefix: webkit
directionChrome Full support 24
Full support 24
No support 23 — 24
Prefixed
Prefixed Implemented with the vendor prefix: webkit
Edge Full support 12Firefox Full support 16
Full support 16
No support 10 — 16
Prefixed
Prefixed Implemented with the vendor prefix: moz
IE Full support 10
Notes
Full support 10
Notes
Notes partial
Opera Full support 15Safari Full support 7WebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 22Opera Android Full support 22Safari iOS Full support 8Samsung Internet Android Full support Yes
keyChrome Full support 24
Full support 24
No support 23 — 24
Prefixed
Prefixed Implemented with the vendor prefix: webkit
Edge Full support 12Firefox Full support 16
Full support 16
No support 10 — 16
Prefixed
Prefixed Implemented with the vendor prefix: moz
IE Full support 10
Notes
Full support 10
Notes
Notes partial
Opera Full support 15Safari Full support 7WebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 22Opera Android Full support 22Safari iOS Full support 8Samsung Internet Android Full support Yes
primaryKeyChrome Full support 24
Full support 24
No support 23 — 24
Prefixed
Prefixed Implemented with the vendor prefix: webkit
Edge Full support 12Firefox Full support 16
Full support 16
No support 10 — 16
Prefixed
Prefixed Implemented with the vendor prefix: moz
IE Full support 10
Notes
Full support 10
Notes
Notes partial
Opera Full support 15Safari Full support 7WebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 22Opera Android Full support 22Safari iOS Full support 8Samsung Internet Android Full support Yes
sourceChrome Full support 24
Full support 24
No support 23 — 24
Prefixed
Prefixed Implemented with the vendor prefix: webkit
Edge Full support 12Firefox Full support 16
Full support 16
No support 10 — 16
Prefixed
Prefixed Implemented with the vendor prefix: moz
IE Full support 10
Notes
Full support 10
Notes
Notes partial
Opera Full support 15Safari Full support 7WebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 22Opera Android Full support 22Safari iOS Full support 8Samsung Internet Android Full support Yes
advanceChrome Full support 24
Full support 24
No support 23 — 24
Prefixed
Prefixed Implemented with the vendor prefix: webkit
Edge Full support 12Firefox Full support 16
Full support 16
No support 10 — 16
Prefixed
Prefixed Implemented with the vendor prefix: moz
IE Full support 10
Notes
Full support 10
Notes
Notes partial
Opera Full support 15Safari Full support 7WebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 22Opera Android Full support 22Safari iOS Full support 8Samsung Internet Android Full support Yes
continueChrome Full support 24
Full support 24
No support 23 — 24
Prefixed
Prefixed Implemented with the vendor prefix: webkit
Edge Full support 12Firefox Full support 16
Full support 16
No support 10 — 16
Prefixed
Prefixed Implemented with the vendor prefix: moz
IE Full support 10
Notes
Full support 10
Notes
Notes partial
Opera Full support 15Safari Full support 7WebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 22Opera Android Full support 22Safari iOS Full support 8Samsung Internet Android Full support Yes
continuePrimaryKeyChrome Full support 58Edge No support NoFirefox Full support 51
Full support 51
No support 10 — 51
Prefixed
Prefixed Implemented with the vendor prefix: moz
IE ? Opera Full support 45Safari Full support 10.1WebView Android Full support 58Chrome Android Full support 58Edge Mobile Full support YesFirefox Android Full support 51Opera Android Full support 45Safari iOS Full support 10.1Samsung Internet Android Full support 7.0
deleteChrome Full support 24
Full support 24
No support 23 — 24
Prefixed
Prefixed Implemented with the vendor prefix: webkit
Edge Full support 12Firefox Full support 16
Full support 16
No support 10 — 16
Prefixed
Prefixed Implemented with the vendor prefix: moz
IE Full support 10
Notes
Full support 10
Notes
Notes partial
Opera Full support 15Safari Full support 7WebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 22Opera Android Full support 22Safari iOS Full support 8Samsung Internet Android Full support Yes
updateChrome Full support 24
Full support 24
No support 23 — 24
Prefixed
Prefixed Implemented with the vendor prefix: webkit
Edge Full support 12Firefox Full support 16
Full support 16
No support 10 — 16
Prefixed
Prefixed Implemented with the vendor prefix: moz
IE Full support 10
Notes
Full support 10
Notes
Notes partial
Opera Full support 15Safari Full support 7WebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 22Opera Android Full support 22Safari iOS Full support 8Samsung Internet Android Full support Yes

Legend

Full support  
Full support
No support  
No support
Compatibility unknown  
Compatibility unknown
See implementation notes.
See implementation notes.
Requires a vendor prefix or different name for use.
Requires a vendor prefix or different name for use.

See also

Document Tags and Contributors

Last updated by: fscholz,