IDBKeyRange: only() static method
The only()
static method of the IDBKeyRange
interface creates a new key range containing a single value.
Note: This feature is available in Web Workers
Syntax
js
IDBKeyRange.only(value)
Parameters
value
-
The value for the new key range.
Return value
IDBKeyRange
: The newly created key range.
Exceptions
DataError
DOMException
-
Thrown if the
value
parameter was not a valid key.
Examples
The following example illustrates how you'd use an only key range. Here we declare
a keyRangeValue = IDBKeyRange.only("A");
— a range that only includes the
value "A". We open a transaction (using IDBTransaction
) and an object
store, and open a Cursor with IDBObjectStore.openCursor
,
declaring keyRangeValue
as its optional key range value. This means that
the cursor will only retrieve the record with the key value "A".
Note: For a more complete example allowing you to experiment with key range, have a look at our IDBKeyRange repo (view the example live too.)
js
function displayData() {
const keyRangeValue = IDBKeyRange.only("A");
const transaction = db.transaction(["fThings"], "readonly");
const objectStore = transaction.objectStore("fThings");
objectStore.openCursor(keyRangeValue).onsuccess = (event) => {
const cursor = event.target.result;
if (cursor) {
const listItem = document.createElement("li");
listItem.textContent = `${cursor.value.fThing}, ${cursor.value.fRating}`;
list.appendChild(listItem);
cursor.continue();
} else {
console.log("Entries all displayed.");
}
};
}
Specifications
Specification |
---|
Indexed Database API 3.0 # ref-for-dom-idbkeyrange-only① |
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).