db 只读特性在 IDBTransaction interface returns the database connection with which this transaction is associated.

注意: 此特征可用于 Web 工作者 .

句法

var myDatabase = transaction.db;
					

IDBDatabase 对象。

范例

In the following code snippet, we open a read/write transaction on our database and add some data to an object store. Note also the functions attached to transaction event handlers to report on the outcome of the transaction opening in the event of success or failure. At the end, we return the associated database connection using db . For a full working example, see our 待办通知 app ( 实时查看范例 )。

// Let us open our database
var DBOpenRequest = window.indexedDB.open("toDoList", 4);
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 addData() function to add the data to the database
  addData();
};
function addData() {
  // Create a new object ready for being inserted into the IDB
  var newItem = [ { taskTitle: "Walk dog", hours: 19, minutes: 30, day: 24, month: "December", year: 2013, notified: "no" } ];
  // open a read/write db transaction, ready for adding the data
  var transaction = db.transaction(["toDoList"], "readwrite");
  // report on the success of opening the transaction
  transaction.oncomplete = function(event) {
    note.innerHTML += '<li>Transaction completed: database modification finished.</li>';
  };
  transaction.onerror = function(event) {
    note.innerHTML += '<li>Transaction not opened due to error. Duplicate items not allowed.</li>';
  };
  // create an object store on the transaction
  var objectStore = transaction.objectStore("toDoList");
  // add our newItem object to the object store
  var objectStoreRequest = objectStore.add(newItem[0]);
  objectStoreRequest.onsuccess = function(event) {
    // report the success of the request (this does not mean the item
    // has been stored successfully in the DB - for that you need transaction.onsuccess)
    note.innerHTML += '<li>Request successful.</li>';
  };
  // Return the database (IDBDatabase) connection with which this transaction is associated
  transaction.db;
};
					

规范

规范 状态 注释
索引数据库 API 2.0
The definition of 'db' in that specification.
推荐
索引数据库 API 草案
The definition of 'db' in that specification.
推荐

浏览器兼容性

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request. 更新 GitHub 上的兼容性数据
桌面 移动
Chrome Edge Firefox Internet Explorer Opera Safari Android webview Chrome for Android Firefox for Android Opera for Android Safari on iOS Samsung Internet
db Chrome 24
24
23 — 57 Prefixed
Prefixed Implemented with the vendor prefix: webkit
Edge 12 Firefox 16
16
10 — 16 Prefixed
Prefixed Implemented with the vendor prefix: moz
IE 部分支持 10 Opera 15 Safari 7 WebView Android Yes
Yes
? — 57 Prefixed
Prefixed Implemented with the vendor prefix: webkit
Chrome Android 25
25
25 — 57 Prefixed
Prefixed Implemented with the vendor prefix: webkit
Firefox Android 22 Opera Android 14 Safari iOS 8 Samsung Internet Android 1.5
1.5
1.5 — 7.0 Prefixed
Prefixed Implemented with the vendor prefix: webkit

图例

完整支持

完整支持

部分支持

部分支持

要求使用供应商前缀或不同名称。

要求使用供应商前缀或不同名称。

另请参阅

元数据

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