indexeddb_examples.js

/** 
 * From the W3C working draft
 * http://www.w3.org/TR/IndexedDB
 */

// synchronously set properties on a database and retrieve a record

var db = indexedDB.open('books', 'Book store', false);
if (db.version !== '1.0') {
  var olddb = indexedDB.open('books', 'Book store');
  olddb.createObjectStore('books', 'isbn');
  olddb.createIndex('BookAuthor', 'books', 'author', false);
  olddb.setVersion("1.0");  
}
// db.version === "1.0";  
var index = db.openIndex('BookAuthor');
var matching = index.get('fred');
if (matching)
  report(matching.isbn, matching.name, matching.author);
else
  report(null);


// asynchronously set properties on a database and retrieve a record

function findFred() {
  db.request.onsuccess = function() {
    var index = db.request.result;
    index.request.onsuccess = function() {
      var matching = index.request.result;
      if (matching)
        report(matching.isbn, matching.name, matching.author);
      else
        report(null);    
    }
    index.get('fred');
  }
  db.openIndex('BookAuthor');
}

indexedDB.request.onsuccess = function() {
  var db = indexedDB.request.result;
  if (db.version !== '1.0') {
    indexedDB.request.onsuccess = function() {
      var olddb = indexedDB.request.result;
      olddb.request.onsuccess = function() {
        olddb.request.onsuccess = function() {
          olddb.request.onsuccess = function() {
            findFred(db);
          }
          olddb.setVersion("1.0");   
        }
        olddb.createIndex('BookAuthor', 'books', 'author', false);        
      }
      olddb.createObjectStore('books', 'isbn');
    }
    indexedDB.open('books', 'Book store');
  }
  findFred(db);
};        
indexedDB.open('books', 'Book store', false);


/* Working with Object Stores */

var db = indexedDB.open('AddressBook', 'Address Book');
if (db.version !== '1') {
   var olddb = indexedDB.open('AddressBook', 'Address Book');
   olddb.createObjectStore('Contact', 'id', true);
   olddb.setVersion('1');
}

// storing a record

var store = db.openObjectStore('Contact');

var lincoln = {name: 'Lincoln', number: '7012'};
var contact = store.put(lincoln);
// contact.id === 1

// retrieving a record

var contact = store.<>get(1);
// contact.name === 'Lincoln'

// updating a record using an in-line key

var abraham = {id: 1, name: 'Abraham', number: '2107'};
store.put(abraham);

// iterating through records using a key range and a cursor

var range = new KeyRange.bound(2, 4);
var cursor = store.openCursor(range);
// each value is a contact and each key is the id for that  
// contact whose id is between 2 and 4, both inclusive
cursor.continue();


/* Working with Indexes */

// creating an index

var db = indexedDB.open('AddressBook', 'Address Book');
if (db.version === '1') {
   var olddb = indexedDB.open('AddressBook', 'Address Book');
   olddb.createObjectStore('Contact', 'id', true);
   olddb.createIndex('ContactName', 'Contact', 'name', false);
   olddb.setVersion('2');
}

// retrieving a record using an index

var index = db.openIndex('ContactName');
var id = index.get('Lincoln');
// id === 1

// iterating through records in an index is similar to
// iterating through records in an object store

var range = new KeyRange.bound('L', 'M');
var cursor = index.openCursor(range);
// each value is a contact and each key is the name for that  
// contact whose name's first letter is either L or M
cursor.continue();


/* Walking through records with a Cursor */

var objects = ...
var cursor = objects.openCursor();
// act on each object and continue the cursor to its end
cursor.continue();

// iterating through records in reverse order

var objects = ...
var count = objects.openCursor(Cursor.PREV);
// act on each object and continue the cursor to its end
cursor.continue();

// single bound, and skipping duplicates

var objects = ...
var range = KeyRange.leftBound(key);
objects.openCursor(range, Cursor.NEXT_NO_DUPLICATE);
// act on each object and continue the cursor to its end
cursor.continue();

// left and right bounds

var objects = ...
var range = KeyRange.bound(start, end);
objects.openCursor(range);
// act on each object and continue the cursor to its end
cursor.continue();

// working with an object from a cursor

console.log('current object', cursor.key, cursor.value);
console.log('there are '+ cursor.count +' objects with the same key');
cursor.value += 1;