--- title: IDBDatabase slug: Web/API/IDBDatabase tags: - API - Database - IDBDatabase - IndexedDB - Interface - NeedsTranslation - Reference - Storage - TopicStub - accessing data - asynchronous access - transactions translation_of: Web/API/IDBDatabase ---
{{APIRef("IndexedDB")}}
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.
{{AvailableInWorkers}}
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.
Inherits from: EventTarget
Fires when a database structure change ({{domxref("IDBOpenDBRequest.onupgradeneeded")}} event or
{{domxref("IDBFactory.deleteDatabase()")}} was requested elsewhere (most probably in another window/tab on the same computer). This is different from the version change transaction (see {{domxref("IDBVersionChangeEvent")}}), but it is related.
In the following code snippet, we open a database asynchronously ({{domxref("IDBFactory")}}), handle success and error cases, and create a new object store in the case that an upgrade is needed ({{ domxref("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');
Specification | Status | Comment |
---|---|---|
{{SpecName('IndexedDB', '#idl-def-IDBDatabase', 'IDBDatabase')}} | {{Spec2('IndexedDB')}} | Initial version |
{{SpecName("IndexedDB 2", "#database-interface", "IDBDatabase")}} | {{Spec2("IndexedDB 2")}} |