IDBDatabase.onversionchange
The onversionchange
event handler of the
IDBDatabase
interface handles the versionchange event, fired when a
database structure change (IDBOpenDBRequest.onupgradeneeded
event or
IDBFactory.deleteDatabase
) was requested elsewhere (most probably in
another window/tab on the same computer).
This is different from the versionchange
transaction (but it is
related).
Note:
This feature is available in Web Workers.Syntax
IDBDatabase.onversionchange = function(event) { ... }
Example
This example shows an IDBOpenDBRequest.onupgradeneeded
block that
creates a new object store; it also includes onerror
and onabort
functions to handle non-success cases, and
an onversionchange function to notify when a database structure change has occurred.
request.onupgradeneeded = function(event) {
var db = event.target.result;
db.onerror = function(event) {
note.innerHTML += '<li>Error opening database.</li>';
};
db.onabort = function(event) {
note.innerHTML += '<li>Database opening aborted!</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 });
note.innerHTML += '<li>Object store created.</li>';
db.onversionchange = function(event) {
note.innerHTML += '<li>a database change has occurred; you should refresh this
browser window, or close it down and use the other open version of
this application, wherever it exists.</li>';
};
};
Specifications
Specification | Status | Comment |
---|---|---|
Indexed Database API 2.0 The definition of 'onversionchange' in that specification. |
Recommendation | |
Indexed Database API 2.0 The definition of 'onversionchange' in that specification. |
Recommendation |
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.)
-
versionchange
event