IDBDatabase

The IDBDatabase interface of the IndexedDB API provides a connection to a database; you can use an IDBDatabase object to open a transaction on your database then create, manipulate, and delete objects (data) in that database. The interface provides the only way to get and manage versions of the database.

Note: This feature is available in Web Workers

Note: Everything you do in IndexedDB always happens in the context of a transaction, representing interactions with data in the database. All objects in IndexedDB — including object stores, indexes, and cursors — are tied to a particular transaction. Thus, you cannot execute commands, access data, or open anything outside of a transaction.

Properties

IDBDatabase.name Read only: A DOMString that contains the name of the connected database.
IDBDatabase.version Read only: A 64-bit integer that contains the version of the connected database. When a database is first created, this attribute is an empty string.
IDBDatabase.objectStoreNames Read only: A DOMStringList that contains a list of the names of the object stores currently in the connected database.

Methods

Inherits from: EventTarget

IDBDatabase.close(): Returns immediately and closes the connection to a database in a separate thread.
IDBDatabase.createMutableFile(): Creates a file handle, allowing files to be stored inside an IndexedDB database.
IDBDatabase.createObjectStore(): Creates and returns a new object store or index.
IDBDatabase.deleteObjectStore(): Destroys the object store with the given name in the connected database, along with any indexes that reference it.
IDBDatabase.transaction(): Immediately returns a transaction object (IDBTransaction) containing the IDBTransaction.objectStore method, which you can use to access your object store. Runs in a separate thread.

Events

Listen to these events using addEventListener() or by assigning an event listener to the oneventname property of this interface.

abort: Fired when a transaction is aborted and bubbles up to the connection object. Also available via the onabort property.
close: Fired when the database connection is unexpectedly closed. Also available via the onclose property.
error: Fired when a request returns an error and the event bubbles up to the connection object. Also available via the onerror property.
versionchange: Fired when a database structure change was requested. Also available via the onversionchange property.

Example

In the following code snippet, we open a database asynchronously (IDBFactory), handle success and error cases, and create a new object store in the case that an upgrade is needed (IDBdatabase). For a complete working example, see our To-do Notifications app (view example live.)

// Let us open our database
var DBOpenRequest = window.indexedDB.open("toDoList", 4);

// these two event handlers act on the IDBDatabase object,
// when the database is 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
  db = DBOpenRequest.result;

  // Run the displayData() function to populate the task
  // list with all the to-do list data already in the IDB
  displayData();
};

// This event handles the event whereby a new version of
// the database needs to be created Either one has not
// been created before, or a new version number has been
// submitted via the window.indexedDB.open line above

DBOpenRequest.onupgradeneeded = function(event) {
  var db = event.target.result;

  db.onerror = function(event) {
    note.innerHTML += '<li>Error loading database.</li>';
  };

  // Create an objectStore for this database using
  // IDBDatabase.createObjectStore

  var objectStore = db.createObjectStore("toDoList", { keyPath: "taskTitle" });

  // define what data items the objectStore will contain

  objectStore.createIndex("hours", "hours", { unique: false });
  objectStore.createIndex("minutes", "minutes", { unique: false });
  objectStore.createIndex("day", "day", { unique: false });
  objectStore.createIndex("month", "month", { unique: false });
  objectStore.createIndex("year", "year", { unique: false });

  objectStore.createIndex("notified", "notified", { unique: false });

  note.innerHTML += '<li>Object store created.</li>';
};

This next line opens up a transaction on the Database, then opens an object store that we can then manipulate the data inside of.

var objectStore = db.transaction('toDoList', 'readwrite').objectStore('toDoList');

Specifications

Specification
Indexed Database API 3.0 (Indexed DB 3.0) # database-interface

Browser compatibility

BCD tables only load in the browser