IDBCursor: continue() method

Available in workers

The continue() method of the IDBCursor interface advances the cursor to the next position along its direction, to the item whose key matches the optional key parameter. If no key is specified, the cursor advances to the immediate next position, based on its direction.

Syntax

continue()
continue(key)

Parameters

• key Optional
  • : The key to position the cursor at.

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.
• DataError DOMException
  • : Thrown if the key parameter has any of the following conditions:
    • The key is not a valid key.
    • The key is less than or equal to this cursor’s position, and the cursor’s direction is next or nextunique.
    • The key is greater than or equal to this cursor’s position and this cursor’s direction is prev or prevunique.
• 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 all the records in the object store. 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 the example live).

function displayData() {
  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.continue();
    } else {
      console.log("Entries all displayed.");
    }
  };
}

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 the example live).