IDBKeyRange: only() static 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 only() static method of the IDBKeyRange
interface creates a new key range containing a single value.
Syntax
IDBKeyRange.only(value)
Parameters
value-
The value for the new key range.
Return value
IDBKeyRange: The newly created key range.
Exceptions
DataErrorDOMException-
Thrown if the
valueparameter 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.)
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
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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).