The advance() method of the IDBCursor interface sets the number of times a cursor should move its position forward.
cursor.advance(count);
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. |
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.');
}
};
}; | Specification | Status | Comment |
|---|---|---|
| Indexed Database API The definition of 'advance()' in that specification. | Recommendation | |
| Indexed Database API 2.0 The definition of 'advance()' in that specification. | Recommendation |
| Desktop | ||||||
|---|---|---|---|---|---|---|
| Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | |
| Basic support | 24
|
12 | 16
|
10
|
15 | 7 |
| Mobile | |||||||
|---|---|---|---|---|---|---|---|
| Android webview | Chrome for Android | Edge Mobile | Firefox for Android | Opera for Android | iOS Safari | Samsung Internet | |
| Basic support | Yes | Yes | Yes | 22 | 22 | 8 | Yes |
IDBDatabase
IDBTransaction
IDBKeyRange
IDBObjectStore
IDBCursor
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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/IDBCursor/advance