IDBKeyRange.only()
The only()
method of the IDBKeyRange
interface creates a new key range containing a single value.
Note: This feature is available in Web Workers
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 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.');
}
};
};
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 example live.)