IDBDatabase: versionchange event

Baseline

Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

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The versionchange event is fired when a database structure change (upgradeneeded event send on an IDBOpenDBRequest or IDBFactory.deleteDatabase) was requested elsewhere (most probably in another window/tab on the same computer).

Syntax

Use the event name in addEventListener():

addEventListener("versionchange", (event) => { })

Alternatively, assign to the event handler property of the interface:

onversionchange = (event) => { }

Event type

A generic Event.

Examples

This example opens a database and, on success, adds a listener to versionchange:

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

dBOpenRequest.onupgradeneeded = (event) => {
  const db = event.target.result;
  // 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 });
};

dBOpenRequest.addEventListener("success", (event) => {
  const db = event.target.result;
  db.addEventListener("versionchange", (event) => {
    console.log("The version of this database has changed");
  });
});

The same example, using the onversionchange event handler property (but note that this replaces other event listeners added using onversionchange and onsuccess, if any):

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

dBOpenRequest.onupgradeneeded = (event) => {
  const db = event.target.result;
  // 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 });
};

dBOpenRequest.onsuccess = (event) => {
  const db = event.target.result;
  db.onversionchange = (event) => {
    console.log("The version of this database has changed");
  };
};