IDBVersionChangeEvent.newVersion - Web APIs 编辑

The newVersion read-only property of the IDBVersionChangeEvent interface returns the new version number of the database.

Note:

Syntax

var newVersion = IDBVersionChangeEvent.newVersion

Value

A 64-bit integer.

Example

In the following code snippet, we make a request to open a database, and include handlers for the success and error cases. These events are fired via the custom IDBVersionChangeEvent interface. 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
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 = DBOpenRequest.result;
};

Specifications

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.)