web api instance method

IDBCursor: advance() method

Available in workers

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

Syntax

advance(count)

Parameters

count
- : The number of times to move the cursor forward.

Return value

None (undefined).

Exceptions

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

TransactionInactiveError DOMException
- : Thrown if this IDBCursor’s transaction is inactive.
TypeError
- : 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.

Examples

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 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 the example live).

function advanceResult() {
  list.textContent = "";
  const transaction = db.transaction(["rushAlbumList"], "readonly");
  const objectStore = transaction.objectStore("rushAlbumList");

  objectStore.openCursor().onsuccess = (event) => {
    const cursor = event.target.result;
    if (cursor) {
      const listItem = document.createElement("li");
      listItem.textContent = `${cursor.value.albumTitle}, ${cursor.value.year}`;
      list.appendChild(listItem);
      cursor.advance(2);
    } else {
      console.log("Every other entry displayed.");
    }
  };
}

Specifications

SpecificationsStandards references are available on the canonical MDN page.

Browser compatibility

Browser compatibilityCompatibility data is available on the canonical MDN page.