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    IDBKeyRange.lowerBound()

    This article is in need of a technical review.

    The lowerBound() method of the IDBKeyRange interface creates a new key range with only a lower bound.

    By default, it includes the lower endpoint value and is closed.

    Syntax

    myKeyRange = IDBKeyRange.lowerBound("A", true);

    Returns

    IDBKeyRange: The newly created key range.

    Exceptions

    This method may raise a DOMException with a DOMError of the following type:

    Exception Description
    DataError

    The value parameter passed was not a valid key.

     

    Example

    The following example illustrates how you'd use a lower bound key range. Here we declare keyRangeValue = IDBKeyRange.lowerBound("F", true); — a range that includes the value "F" and everthing after it. 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 "F" and all that come after it. If we used IDBKeyRange.lowerBound("F", true);, then the range would not include "F"; only the values after it.

    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.lowerBound("F");
    
      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

    bound
    The value of the lower bound.
    open
    Optional. If false (default value), the range includes the lower-bound value.

    Specification

    Specification Status Comment
    Indexed Database API
    The definition of 'lowerBound()' in that specification.
    Candidate Recommendation  

    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
    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 Not supported

    See also

    Document Tags and Contributors

    Contributors to this page: fscholz, chrisdavidmills
    Last updated by: fscholz,