IDBKeyRange.only()
The only()
method of the IDBKeyRange
interface creates a new key range containing a single value.
Syntax
myKeyRange = IDBKeyRange.only("A");
Returns
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.'); } }; };
Parameters
- value
- The single value in the key range.
Specification
Specification | Status | Comment |
---|---|---|
Indexed Database API The definition of 'only' in that specification. |
Editor's Draft |
Browser compatibility
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
---|---|---|---|---|---|
Basic support | 23webkit 24 |
10 moz 16.0 (16.0) |
10, partial | 15 | 7.1 |
Available in workers | (Yes) | 37.0 (37.0) | ? | (Yes) | ? |
Feature | Android | Firefox Mobile (Gecko) | Firefox OS | IE Phone | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|
Basic support | 4.4 | 22.0 (22.0) | 1.0.1 | 10 | 22 | 8 |
Available in workers | (Yes) | 37.0 (37.0) | (Yes) | ? | (Yes) | ? |
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.)
License
© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-us/docs/web/api/idbkeyrange/only