IDBCursor.direction

Syntax

cursor.direction;

Value

A string (defined by the IDBCursorDirection enum) indicating the direction in which the cursor is traversing the data. Possible values are:

Value	Description
next	This direction causes the cursor to be opened at the start of the source.
nextunique	This direction causes the cursor to be opened at the start of the source. For every key with duplicate values, only the first record is yielded.
prev	This direction causes the cursor to be opened at the end of the source.
prevunique	This direction causes the cursor to be opened at the end of the source. For every key with duplicate values, only the first record is yielded.

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 direction of the cursor, something like this:

prev

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 backwards() {
  list.innerHTML = '';
  var transaction = db.transaction(['rushAlbumList'], 'readonly');
  var objectStore = transaction.objectStore('rushAlbumList');

  objectStore.openCursor(null,'prev').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);  
          
        console.log(cursor.direction);
        cursor.continue();
      } else {
        console.log('Entries displayed backwards.');
      }
  };
};

Specifications

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

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.)