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.

Nota: Esta característica está disponible en 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.

Methods

Inherits from: EventTarget

IDBDatabase.close() (en-US): Returns immediately and closes the connection to a database in a separate thread.
IDBDatabase.createObjectStore() (en-US): Creates and returns a new object store or index.
IDBDatabase.deleteObjectStore() (en-US): 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 (en-US)) containing the IDBTransaction.objectStore (en-US) method, which you can use to access your object store. Runs in a separate thread.

Properties

IDBDatabase.name (en-US) Read only: A DOMString that contains the name of the connected database.
IDBDatabase.version (en-US) 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 (en-US) Read only: A DOMStringList (en-US) that contains a list of the names of the object stores currently in the connected database.

Event handlers

IDBDatabase.onabort (en-US): Fires when access of the database is aborted.
IDBDatabase.onclose (en-US): Fires when the close event occurs; this happens when the database is unexpectedly closed, such as during application shutdown.
IDBDatabase.onerror (en-US): Fires when access to the database fails.
IDBDatabase.onversionchange (en-US): Fires when a database structure change (IDBOpenDBRequest.onupgradeneeded (en-US) event or IDBFactory.deleteDatabase() (en-US) was requested elsewhere (most probably in another window/tab on the same computer). This is different from the version change transaction (see IDBVersionChangeEvent (en-US)), but it is related.

Example

In the following code snippet, we open a database asynchronously (IDBFactory (en-US)), 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').objectStore('toDoList');

Specifications

Specification	Status	Comment
Indexed Database API 2.0 La definición de 'IDBDatabase' en esta especificación.	Recommendation	Initial version
Indexed Database API 2.0 La definición de 'IDBDatabase' en esta especificación.	Recommendation

Browser compatibility

BCD tables only load in the browser