The advance() method of the IDBCursor interface sets the number of times a cursor should move its position forward.
Syntax
cursor.advance(count);
Parameters
count- The number of times to move the cursor forward.
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 2.0 The definition of 'advance()' in that specification. |
Recommendation | |
| Indexed Database API Draft The definition of 'advance()' in that specification. |
Recommendation |
Browser compatibility
| Desktop | Mobile | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
advance | Chrome
Full support
24
| Edge Full support 12 | Firefox
Full support
16
| IE Partial support 10 | Opera Full support 15 | Safari Full support 7 | WebView Android Full support Yes | Chrome Android Full support Yes | Firefox Android Full support 22 | Opera Android Full support 14 | Safari iOS Full support 8 | Samsung Internet Android Full support Yes |
Legend
- Full support
- Full support
- Partial support
- Partial support
- Requires a vendor prefix or different name for use.
- Requires a vendor prefix or different name for use.
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.)
