IDBFactory - Web APIs 编辑

The IDBFactory interface of the IndexedDB API lets applications asynchronously access the indexed databases. The object that implements the interface is window.indexedDB. You open — that is, create and access — and delete a database with this object, and not directly with IDBFactory.

Note:

Methods

IDBFactory.open

The current method to request opening a connection to a database.

IDBFactory.deleteDatabase

A method to request the deletion of a database.

IDBFactory.cmp

A method that compares two keys and returns a result indicating which one is greater in value.

IDBFactory.databases

A method that returns a list of all available databases, including their names and versions.

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.)

// 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) {
  console.error("Error loading database.");
};

DBOpenRequest.onsuccess = function(event) {
  console.info("Database initialised.");

  // 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.)