The IDBVersionChangeEvent interface of the IndexedDB API indicates that the version of the database has changed, as the result of an onupgradeneeded event handler function.

IDBVersionChangeEvent()

Creates and returns a new IDBVersionChangeEvent object which is used to represent when a version of the database has changed.

Also inherits properties from its parent, Event interface.

IDBVersionChangeEvent.oldVersion Read only

Returns the old version of the database.

IDBVersionChangeEvent.newVersion Read only

Returns the new version of the database.

No specific method, but inherits methods from its parent, Event interface.

In the following code snippet, we make a request to open a database, and include handlers for the success and error cases. Upon a version change (after an upgradeneeded event), the success event will implement the IDBVersionChangeEvent interface. For a full working example, see our To-do Notifications app (view example live).

const note = document.querySelector("ul");

// Let us open version 4 of our database
const DBOpenRequest = window.indexedDB.open("toDoList", 4);

// these two event handlers act on the database being opened successfully, or not
DBOpenRequest.onerror = (event) => {
  note.innerHTML += "<li>Error loading database.</li>";
};

DBOpenRequest.onsuccess = (event) => {
  note.innerHTML += "<li>Database initialized.</li>";

  // store the result of opening the database in the db variable. This is used a lot later on, for opening transactions and suchlike.
  const db = DBOpenRequest.result;
};

• 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).