IDBCursor.primaryKey

The primaryKey read-only property of the IDBCursor interface returns the cursor's current effective 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.

Note: This feature is available in Web Workers.

Syntax

var value = cursor.primaryKey;

Value

A value of any data type.

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. Within each iteration we log the primary key of the cursor to the console, something like this (its the album title in each case, which is our primarykey):

Hemispheres

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

Specifications

Specification Status Comment
Indexed Database API
The definition of 'primaryKey' in that specification.
Recommendation  
Indexed Database API 2.0
The definition of 'primaryKey' in that specification.
Recommendation  

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidiOS SafariSamsung Internet
Basic supportChrome Full support 24
Full support 24
No support 23 — 24
Prefixed
Prefixed Requires the vendor prefix: webkit
Edge Full support 12Firefox Full support 16
Full support 16
No support 10 — 16
Prefixed
Prefixed Requires 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
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

Contributors to this page: fscholz, jpmedley, arronei, libbymc, chrisdavidmills, teoli
Last updated by: fscholz,