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The advance()
method of the IDBCursor
interface sets the number times a cursor should move its position forward.
Syntax
cursor.advance(count);
Parameters
- count
- The number of times to move the cursor forward.
Returns
Void.
Exceptions
This method may raise a DOMException
of one of the following types:
Exception | Description |
---|---|
TransactionInactiveError |
This IDBCursor's transaction is inactive. |
TypeError |
The value passed into the count parameter was zero or a negative number. |
InvalidStateError |
The cursor is currently being iterated or has iterated past its end. |
Example
In this simple fragment we create a transaction, retrieve an object store, then use a cursor to iterate through the records in the object store. Here we use cursor.advance(2)
to jump 2 places forward each time, meaning that only every other result will be displayed. advance()
works in a similar way to IDBCursor.continue
, except that it allows you to jump multiple records at a time, not just always go onto the next record.
Note that in each iteration of the loop, you can grab data from the current record under the cursor object using cursor.value.foo
. For a complete working example, see our IDBCursor example (view example live.)
function advanceResult() {
list.innerHTML = '';
var transaction = db.transaction(['rushAlbumList'], "readonly");
var objectStore = transaction.objectStore('rushAlbumList');
objectStore.openCursor().onsuccess = function(event) {
var cursor = event.target.result;
if(cursor) {
var listItem = document.createElement('li');
listItem.innerHTML = '<strong>' + cursor.value.albumTitle + '</strong>, ' + cursor.value.year;
list.appendChild(listItem);
cursor.advance(2);
} else {
console.log('Every other entry displayed.');
}
};
};
Specifications
Specification | Status | Comment |
---|---|---|
Indexed Database API The definition of 'advance()' in that specification. |
Editor's Draft |
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.)