The db
read-only property of the IDBTransaction
interface returns the database connection with which this transaction is associated.
Note: This feature is available in Web Workers.
Syntax
var myDatabase = transaction.db;
Value
An IDBDatabase
object.
Example
In the following code snippet, we open a read/write transaction on our database and add some data to an object store. Note also the functions attached to transaction event handlers to report on the outcome of the transaction opening in the event of success or failure. At the end, we return the associated database connection using db
. For a full working example, see our To-do Notifications app (view example live.)
// Let us open our database var DBOpenRequest = window.indexedDB.open("toDoList", 4); 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 addData() function to add the data to the database addData(); }; function addData() { // Create a new object ready for being inserted into the IDB var newItem = [ { taskTitle: "Walk dog", hours: 19, minutes: 30, day: 24, month: "December", year: 2013, notified: "no" } ]; // open a read/write db transaction, ready for adding the data var transaction = db.transaction(["toDoList"], "readwrite"); // report on the success of opening the transaction transaction.oncomplete = function(event) { note.innerHTML += '<li>Transaction completed: database modification finished.</li>'; }; transaction.onerror = function(event) { note.innerHTML += '<li>Transaction not opened due to error. Duplicate items not allowed.</li>'; }; // create an object store on the transaction var objectStore = transaction.objectStore("toDoList"); // add our newItem object to the object store var objectStoreRequest = objectStore.add(newItem[0]); objectStoreRequest.onsuccess = function(event) { // report the success of the request (this does not mean the item // has been stored successfully in the DB - for that you need transaction.onsuccess) note.innerHTML += '<li>Request successful.</li>'; }; // Return the database (IDBDatabase) connection with which this transaction is associated transaction.db; };
Specification
Specification | Status | Comment |
---|---|---|
Indexed Database API The definition of 'db' in that specification. |
Recommendation | |
Indexed Database API 2.0 The definition of 'db' in that specification. |
Editor's Draft |
Browser compatibility
Feature | Chrome | Edge | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
---|---|---|---|---|---|---|
Basic support | 23webkit 24 (unprefixed) |
(Yes) | 10 moz 16.0 (16.0) |
10, partial | 15 | 7.1 |
Available in workers | (Yes) | ? | 37.0 (37.0) | ? | (Yes) | ? |
Indexed Database 2.0 | 58 | ? | ? | ? | 45 | ? |
Feature | Android Webview | Chrome for Android | Edge | Firefox Mobile (Gecko) | Firefox OS | IE Phone | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|---|---|
Basic support | (Yes) | (Yes) | (Yes) | 22.0 (22.0) | 1.0.1 | 10 | 22 | 8 |
Available in workers | (Yes) | (Yes) | ? | 37.0 (37.0) | (Yes) | ? | (Yes) | ? |
Indexed Database 2.0 | 58 | 58 | ? | ? | ? | ? | 45 | ? |
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.)