The only() method of the IDBKeyRange interface creates a new key range containing a single value.
Syntax
var myIDBKeyRange = IDBKeyRange.only(value);
Parameters
value is the value for the new key range.
Return value
IDBKeyRange: The newly created key range.
Exceptions
This method may raise a DOMException of the following types:
| Exception | Description |
|---|---|
| DataError |
The value parameter passed was not a valid key. |
Example
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-example repo (view the example live too.)
function displayData() {
var keyRangeValue = IDBKeyRange.only("A");
var transaction = db.transaction(['fThings'], 'readonly');
var objectStore = transaction.objectStore('fThings');
objectStore.openCursor(keyRangeValue).onsuccess = function(event) {
var cursor = event.target.result;
if(cursor) {
var listItem = document.createElement('li');
listItem.innerHTML = '<strong>' + cursor.value.fThing + '</strong>, ' + cursor.value.fRating;
list.appendChild(listItem);
cursor.continue();
} else {
console.log('Entries all displayed.');
}
};
};
Specification
| Specification | Status | Comment |
|---|---|---|
| Indexed Database API The definition of 'only' in that specification. |
Recommendation | |
| Indexed Database API 2.0 The definition of 'only' in that specification. |
Editor's Draft |
Browser compatibility
| Feature | Chrome | Edge | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
|---|---|---|---|---|---|---|
| Basic support | 23webkit 24 (unprefixed) |
(Yes) | 10 moz 16.0 (16.0) |
10, partial | 15 | 7.1 |
| Available in workers | (Yes) | (Yes) | 37.0 (37.0) | ? | (Yes) | ? |
| Indexed Database 2.0 | 58 | ? | ? | ? | 45 | ? |
| Feature | Android Webview | Chrome for Android | Edge | Firefox Mobile (Gecko) | Firefox OS | IE Phone | Opera Mobile | Safari Mobile |
|---|---|---|---|---|---|---|---|---|
| Basic support | (Yes) | (Yes) | (Yes) | 22.0 (22.0) | 1.0.1 | 10 | 22 | 8 |
| Available in workers | (Yes) | (Yes) | (Yes) | 37.0 (37.0) | (Yes) | ? | (Yes) | ? |
| Indexed Database 2.0 | 58 | 58 | ? | ? | ? | ? | 45 | ? |
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 example live.)