dom / latest / idbkeyrange / only.html /

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

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.

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() {
  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

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
only
23
12
10
10
15
7
4.4
25
22
14
8
1.5

See also

© 2005–2021 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/IDBKeyRange/only