IDBCursor.advance()

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

Note: This feature is available in Web Workers

Syntax

cursor.advance(count);

Parameters

count

The number of times to move the cursor forward.

Exceptions

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

TransactionInactiveError DOMException

Thrown if this IDBCursor's transaction is inactive.

TypeError DOMException

Thrown if the value passed into the count parameter was zero or a negative number.

InvalidStateError DOMException

Thrown if the cursor is currently being iterated or has iterated past its end.

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.textContent = '';
  const transaction = db.transaction(['rushAlbumList'], "readonly");
  const objectStore = transaction.objectStore('rushAlbumList');

  objectStore.openCursor().onsuccess = function(event) {
    const cursor = event.target.result;
    if(cursor) {
      const 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.');
    }
  };
};

Specifications

Specification
Indexed Database API 3.0 (Indexed DB 3.0)
# ref-for-dom-idbcursor-advance①

Browser compatibility

BCD tables only load in the browser

See also