IDBOpenDBRequest: upgradeneeded event

The upgradeneeded event is fired when an attempt was made to open a database with a version number higher than its current version.

This event is not cancelable and does not bubble.

Syntax

Use the event name in methods like addEventListener(), or set an event handler property.

js
addEventListener("upgradeneeded", (event) => {});

onupgradeneeded = (event) => {};

Event type

An IDBVersionChangeEvent. Inherits from Event.

Event IDBVersionChangeEvent

Event properties

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.

Examples

This example opens a database and handles the upgradeneeded event by making any necessary updates to the object store.

js
// Open the database
const dBOpenRequest = window.indexedDB.open("toDoList", 4);

dBOpenRequest.addEventListener("upgradeneeded", (event) => {
  const db = event.target.result;
  console.log(`Upgrading to version ${db.version}`);

  // Create an objectStore for this database
  const objectStore = db.createObjectStore("toDoList", {
    keyPath: "taskTitle",
  });

  // define what data items the objectStore will contain
  objectStore.createIndex("hours", "hours", { unique: false });
  objectStore.createIndex("minutes", "minutes", { unique: false });
  objectStore.createIndex("day", "day", { unique: false });
  objectStore.createIndex("month", "month", { unique: false });
  objectStore.createIndex("year", "year", { unique: false });
});

This is the same example, but uses the onupgradeneeded event handler property.

js
// Open the database
const dBOpenRequest = window.indexedDB.open("toDoList", 4);

dBOpenRequest.onupgradeneeded = (event) => {
  const db = event.target.result;
  console.log(`Upgrading to version ${db.version}`);

  // Create an objectStore for this database
  const objectStore = db.createObjectStore("toDoList", {
    keyPath: "taskTitle",
  });

  // define what data items the objectStore will contain
  objectStore.createIndex("hours", "hours", { unique: false });
  objectStore.createIndex("minutes", "minutes", { unique: false });
  objectStore.createIndex("day", "day", { unique: false });
  objectStore.createIndex("month", "month", { unique: false });
  objectStore.createIndex("year", "year", { unique: false });
};

Browser compatibility

BCD tables only load in the browser

See also