IDBCursor: delete() method
Baseline
Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
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:
TransactionInactiveErrorDOMException-
Thrown if this IDBCursor's transaction is inactive.
ReadOnlyErrorDOMException-
Thrown if the transaction mode is read-only.
InvalidStateErrorDOMException-
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
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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).