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The IDBOpenDBRequest interface of the IndexedDB API provides access to the results of requests to open or delete databases (performed using and IDBFactory.deleteDatabase), using specific event handler attributes.

Note: This feature is available in Web Workers.


Also inherits methods from its parents IDBRequest and EventTarget.


The event handler for the blocked event. This event is triggered when the upgradeneeded event should be triggered because of a version change but the database is still in use (i.e. not closed) somewhere, even after the versionchange event was sent.
The event handler for the upgradeneeded event, fired when a database of a bigger version number than the existing stored database is loaded.


No methods, but inherits methods from its parents IDBRequest and EventTarget.


In the following example you can see the onupgradeneeded handler being used to update the database structure if a database with a higher version number is loaded. For a full working example, see our To-do Notifications app (view example live.)

var db;

// Let us open our database
var DBOpenRequest ="toDoList", 4);

// these event handlers act on the database being opened.
DBOpenRequest.onerror = function(event) {
  note.innerHTML += '<li>Error loading database.</li>';

DBOpenRequest.onsuccess = function(event) {
  note.innerHTML += '<li>Database initialised.</li>';
  // store the result of opening the database in the db
  // variable. This is used a lot below
  db = DBOpenRequest.result;
  // Run the displayData() function to populate the task
  // listwith all the to-do list data already in the IDB

// This event handles the event whereby a new version of
// the database needs to be created Either one has not
// been created before, or a new version number has been
// submitted via the line above
// it is only implemented in recent browsers
DBOpenRequest.onupgradeneeded = function(event) {
  var db = this.result;
  db.onerror = function(event) {
    note.innerHTML += '<li>Error loading database.</li>';

  // Create an objectStore for this database   
  var 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 });
  objectStore.createIndex("notified", "notified", { unique: false });


Specification Status Comment
Indexed Database API
The definition of 'IDBOpenDBRequest' in that specification.
Recommendation Initial definition
Indexed Database API 2.0
The definition of 'IDBOpenDBRequest' in that specification.
Editor's Draft  

Browser compatibility

Feature Chrome Edge Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 23webkit
24 (unprefixed)
(Yes) 10 moz
16.0 (16.0)
10, partial 15 7.1
Available in workers (Yes) ? 37.0 (37.0) ? (Yes) ?
Indexed Database 2.0 58 ? ? ? 45 ?
Feature Android Webview Chrome for Android Edge Firefox Mobile (Gecko) Firefox OS IE Phone Opera Mobile Safari Mobile
Basic support (Yes) (Yes) (Yes) 22.0 (22.0) 1.0.1 10 22 8
Available in workers (Yes) (Yes) ? 37.0 (37.0) (Yes) ? (Yes) ?
Indexed Database 2.0 58 58 ? ? ? ? 45 ?

See also


 最終更新者: jpmedley,