The db
property of the IDBTransaction
interface returns the database connection with which this transaction is associated.
Note: This feature is available in Web Workers.
SyntaxEdit
var myDatabase = transaction.db;
Value
An IDBDatabase
object.
ExampleEdit
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 our new item going into the database
note.innerHTML += '<li>New item added to database.</li>';
};
// Return the database (IDBDatabase) connection with which this transaction is associated
transaction.db;
};
SpecificationEdit
Specification | Status | Comment |
---|---|---|
Indexed Database API The definition of 'db' in that specification. |
Editor's Draft |
Browser compatibilityEdit
See alsoEdit
- 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.)