IDBFactory - Web API 接口参考 编辑

IndexedDB API 的IDBFactory 接口让程序可以异步存取 indexed databases。window.indexedDB 对象实现了这个接口。你可以通过这个对象而不是直接使用IDBFactory接口打开—— 创建或者连接 —— 和删除一个数据库。

Methods

IDBFactory.open

请求打开一个数据库的连接（connection to a database）。

IDBFactory.deleteDatabase

请求删除数据库。

IDBFactory.cmp

比较两个键的方法并返回一个结果，表明哪个值更大。

过时的Methods

IDBFactory.open, the original version

一个被废弃的方法请求打开一个数据库的连接，仍然在一些浏览器中被实施(connection to a database).

Example

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 = window.indexedDB.open("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;
};

Specifications

Specification	Status	Comment
Indexed Database API IDBFactory	Recommendation

Browser compatibility

We're converting our compatibility data into a machine-readable JSON format. This compatibility table still uses the old format, because we haven't yet converted the data it contains. Find out how you can help!

• Desktop
• Mobile

Feature	Chrome	Firefox (Gecko)	Internet Explorer	Opera	Safari (WebKit)
Basic support	23webkit 24	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

• 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 example live.)