IDBFactory
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
(en-US)-
请求删除数据库。
IDBFactory.cmp
(en-US)-
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
(en-US), 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.)
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.)