IDBCursor.advance()

The advance() method of the IDBCursor interface sets the number times a cursor should move its position forward.

Syntax

cursor.advance(2);

Returns

Void.

Exceptions

This method may raise a DOMException with a DOMError of one of the following types:

Example

In this simple fragment we create a transaction, retrieve an object store, then use a cursor to iterate through the records in the object store. Here we use cursor.advance(2) to jump 2 places forward each time, meaning that only every other result will be displayed. advance() works in a similar way to IDBCursor.continue, except that it allows you to jump multiple records at a time, not just always go onto the next record.

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 advanceResult() {
  list.innerHTML = '';
  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 = '<strong>' + cursor.value.albumTitle + '</strong>, ' + cursor.value.year;
      list.appendChild(listItem);  
      cursor.advance(2);
    } else {
      console.log('Every other entry displayed.');
    }
  };
};

Parameters

count

The number of advances forward the cursor should make.

Specifications

Browser compatibility

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.)