The IDBOpenDBRequest
interface of the IndexedDB API provides access to the results of requests to open or delete databases (performed using IDBFactory.open
and IDBFactory.deleteDatabase
), using specific event handler attributes.
Inherits from: IDBRequest
Note: This feature is available in Web Workers.
Methods
No methods.
Properties
Event handlers
IDBOpenDBRequest.onblocked
- The event handler for the blocked event. This event is triggered when the
upgradeneeded
event should be triggered because of a version change but the database is still in use (i.e. not closed) somewhere, even after theversionchange
event was sent. IDBOpenDBRequest.onupgradeneeded
- The event handler for the
upgradeneeded
event, fired when a database of a bigger version number than the existing stored database is loaded.
Example
In the following example you can see the onupgradeneeded handler being used to update the database structure if a database with a higher version number is loaded. For a full working example, see our To-do Notifications app (view example live.)
var db; // Let us open 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) { 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 below 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 //it is only implemented in recent browsers 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 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 }); };
Specifications
Specification | Status | Comment |
---|---|---|
Indexed Database API The definition of 'IDBOpenDBRequest' in that specification. |
Recommendation |
Browser compatibility
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
---|---|---|---|---|---|
Basic support | 23webkit 24 |
10 moz 16.0 (16.0) |
10, partial | 15 | 7.1 |
Available in workers | (Yes) | 37.0 (37.0) | ? | (Yes) | ? |
Feature | Android | Firefox Mobile (Gecko) | Firefox OS | IE Phone | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|
Basic support | 4.4 | 22.0 (22.0) | 1.0.1 | 10 | 22 | 8 |
Available in workers | (Yes) | 37.0 (37.0) | (Yes) | ? | (Yes) | ? |
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.)
Document Tags and Contributors
Tags:
Contributors to this page:
jpmedley,
chrisdavidmills,
fscholz,
mattandrews,
pdm,
teoli,
julienw,
scottrowe
Last updated by:
jpmedley,