openCursor method

Returns a cursor object positioned at the first record object in a data source, optionally filtered by a key range and ordered by a direction.

Syntax

Parameters

range [in, optional]

Type: any

A key range limiting the cursor to a specific set of values.

direction [in, optional]

Type: DOMString

Indicates the direction of traversal and whether duplicate values are included.

Value	Meaning
"next"	The cursor contains duplicate values and is traversing key values in ascending order.
"nextunique"	The cursor contains only unique values and is traversing key values in ascending order.
"prev"	The cursor contains duplicate values and is traversing key values in descending order.
"prevunique"	The cursor contains only unique values and is traversing key values in descending order.

 

Exceptions

This method can throw the following DOMException exceptions:

Note  As of a Windows Store app using JavaScript, the code property is deprecated in favor of the name property, which is preferred for standards compliance and future compatibility.

Standards information

• Indexed Database API

Examples

The following example illustrates a function designed to return a record object from an object store; the function supports an optional parameter (sIndexName) that specifies the name of an index. If the sIndexName parameter specifies a value, the function uses that value to open a cursor using an index. If the parameter isn't specified, the function opens the cursor directly.

function getCard( aValue, fnCallback, sIndexName ) {

  if ( hIxHandle == null ) {
     handleError( "Can't open database (invalid handle)." );
  } else
       try {

          sObjectStore = getCardStoreName();        
          var hTransaction = hDBHandle.transaction( sObjectStore, "readonly" );
          var hObjectStore = hTransaction.objectStore( sObjectStore );
          var hRequest = null;
          
          if ( sIndexName == null ) {
             hRequest = hObjectStore.openCursor( aValue );
          } else {
             var hIndex = hObjectStore.index( sIndexName ); 
             hRequest = hIndex.openCursor( aValue );
          }
          hRequest.onerror = handleRequestEvent;
          hRequest.onsuccess = function( evt ) {
             handleRequestEvent( evt );
             if ( fnCallback != null ) {
                var oResult = null; // assume no result.
                if ( evt.target.result != null ) {
                   oResult = evt.target.result.value; 
                }
                fnCallback( oResult );          
             }
          }
       } catch( ex ) {
         handleError( ex.message );
       }   
}

See also

IDBObjectStore

IDBIndex

IDBCursor

Build date: 11/22/2012