IDBFactory
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since September 2021.
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 已弃用-
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.)
js
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 |
---|
Indexed Database API 3.0 # factory-interface |
Browser compatibility
BCD tables only load in the browser
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.)