The advance()
method of the IDBCursor
interface sets the number of times a cursor should move its position forward.
Note: This feature is available in Web Workers
The advance()
method of the IDBCursor
interface sets the number of times a cursor should move its position forward.
Note: This feature is available in Web Workers
js
advance(count)
count
The number of times to move the cursor forward.
None (undefined
).
This method may raise a DOMException
of one of the following types:
TransactionInactiveError
DOMException
Thrown if this IDBCursor's transaction is inactive.
TypeError
Thrown if the value passed into the count
parameter was zero or a negative number.
InvalidStateError
DOMException
Thrown if 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 the example live).
js
function advanceResult() { list.textContent = ""; const transaction = db.transaction(["rushAlbumList"], "readonly"); const objectStore = transaction.objectStore("rushAlbumList"); objectStore.openCursor().onsuccess = (event) => { const cursor = event.target.result; if (cursor) { const listItem = document.createElement("li"); listItem.textContent = `${cursor.value.albumTitle}, ${cursor.value.year}`; list.appendChild(listItem); cursor.advance(2); } else { console.log("Every other entry displayed."); } }; }
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | WebView Android | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | |
advance |
23 | 12 | 10 | 10 | 15 | 8 | 4.4 | 25 | 22 | 14 | 8 | 1.5 |
IDBDatabase
IDBTransaction
IDBKeyRange
IDBObjectStore
IDBCursor
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https://developer.mozilla.org/en-US/docs/Web/API/IDBCursor/advance