The IDBFactory interface of the IndexedDB API lets applications asynchronously access the indexed databases. The object that implements the interface is window.indexedDB. You open — that is, create and access — and delete a database with this object, and not directly with IDBFactory.

请求打开一个数据库的连接(connection to a database)。
A method that compares two keys and returns a result indicating which one is greater in value.

Obsolete methods, the original version
An obsolete method to request opening a connection to a database, still implemented by some browsers.


In the following code snippet, we make a request to open a database, and include handlers for the success and error cases. For a full working example, see our To-do Notifications app (view example live.)

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

// In the following line, you should include the prefixes of implementations you want to test.
window.indexedDB = window.indexedDB || window.mozIndexedDB || window.webkitIndexedDB || window.msIndexedDB;
// DON'T use "var indexedDB = ..." if you're not in a function.
// Moreover, you may need references to some window.IDB* objects:
window.IDBTransaction = window.IDBTransaction || window.webkitIDBTransaction || window.msIDBTransaction;
window.IDBKeyRange = window.IDBKeyRange || window.webkitIDBKeyRange || window.msIDBKeyRange;
// (Mozilla has never prefixed these objects, so we don't need window.mozIDB*)

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

// these two event handlers act on the database being opened successfully, or not
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 later on, for opening transactions and suchlike.
  db = request.result;


Specification Status Comment
Indexed Database API

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 23webkit
10 moz
16.0 (16.0)
10, partial 15 7.1
Feature Android Firefox Mobile (Gecko) Firefox OS IE Phone Opera Mobile Safari Mobile
Basic support 4.4 22.0 (22.0) 1.0.1 10 22 未实现

Be careful in Chrome as it still implements the old specification along with the new one. Similarly it still has the prefixed webkitIndexedDB property even if the unprefixed indexedDB is present.

See also


 此页面的贡献者: w05163, teoli
 最后编辑者: w05163,