IDBCursor: delete() method
Note: This feature is available in Web Workers.
The delete()
method of the IDBCursor
interface returns an IDBRequest
object, and, in a separate thread,
deletes the record at the cursor's position, without changing the cursor's position.
Once the record is deleted, the cursor's value is set to null.
Be aware that you can't call delete()
(or
IDBCursor.update()
) on cursors obtained from
IDBIndex.openKeyCursor()
. For such needs, you have to use
IDBIndex.openCursor()
instead.
Syntax
delete()
Parameters
None.
Return value
An IDBRequest
object on which subsequent events related to this
operation are fired.
If the operation is successful, the value of the request's result
property is undefined
.
Exceptions
This method may raise a DOMException
of one of the following types:
TransactionInactiveError
DOMException
-
Thrown if this IDBCursor's transaction is inactive.
ReadOnlyError
DOMException
-
Thrown if the transaction mode is read-only.
InvalidStateError
DOMException
-
Thrown if the cursor was created using
IDBindex.openKeyCursor
, is currently being iterated, or has iterated past its end.
Examples
In this simple fragment we create a transaction, retrieve an object store, then use a
cursor to iterate through all the records in the object store. If the
albumTitle
of the current cursor is "Grace under pressure", we delete that
entire record using const request = cursor.delete();
.
The cursor does not require us to select the data based on a key; we can just grab all
of it. Also 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).
function deleteResult() {
list.textContent = "";
const transaction = db.transaction(["rushAlbumList"], "readwrite");
const objectStore = transaction.objectStore("rushAlbumList");
objectStore.openCursor().onsuccess = (event) => {
const cursor = event.target.result;
if (cursor) {
if (cursor.value.albumTitle === "Grace under pressure") {
const request = cursor.delete();
request.onsuccess = () => {
console.log(
"Deleted that mediocre album from 1984. Even Power windows is better.",
);
};
} else {
const listItem = document.createElement("li");
listItem.textContent = `${cursor.value.albumTitle}, ${cursor.value.year}`;
list.appendChild(listItem);
}
cursor.continue();
} else {
console.log("Entries displayed.");
}
};
}
Specifications
Specification |
---|
Indexed Database API 3.0 # ref-for-dom-idbcursor-delete① |
Browser compatibility
BCD tables only load in the browser
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 the example live).