// This is what our customer data looks like.
var customerData = [
  { ssn: "444-44-4444", name: "Bill", age: 35, email: "bill@company.com" },
  { ssn: "555-55-5555", name: "Donna", age: 32, email: "donna@home.org" }
];
var dbName = "CustomerDB";
 
// Open database with version=2. Use integer valueonly ! Not 1.1, 1.2 etc.
var request = indexedDB.open(dbName, 2);

  request.onerror = function(event) {
  // Handle errors.
  console.log("request.onerror errcode=" + event.target.error.name);
};
request.onupgradeneeded = function(event) {
  console.log("request.onupgradeneeded, we are creating a new version of the dataBase");
  var db = event.target.result;
 
  // Create an objectStore to hold information about our customers. We're
  // going to use "ssn" as our key path because it's guaranteed to be
  // unique.
  var objectStore = db.createObjectStore("customers", { keyPath: "ssn" });
 
  // Create an index to search customers by name. We may have duplicates
  // so we can't use a unique index.
  objectStore.createIndex("name", "name", { unique: false });
 
  // Create an index to search customers by email. We want to ensure that
  // no two customers have the same email, so use a unique index.
  objectStore.createIndex("email", "email", { unique: true });
 
  // Store values in the newly created objectStore.
  for (var i in customerData) {
    objectStore.add(customerData[i]);
  }
};

  // Handle errors.
  console.log("request.onsuccess, database opened, now we can add / remove / look for data in it!");
    // The result is the database itself
  var db = event.target.result;  
};

Example to add a record to indexedDB

  function addACustomer() {
   // 1 - get a transaction on the "customers" object store
   // in readwrite, as we are going to insert a new object
   var transaction = db.transaction(["customers"], "readwrite");
   // Do something when all the data is added to the database.
   // This callback is called after transaction has been completely
   // executed (committed)
   transaction.oncomplete = function(event) {
       alert("All done!");
   };
   // This callback is called in case of error (rollback)
   transaction.onerror = function(event) {
      console.log("transaction.onerror errcode=" + event.target.error.name);
   };
   // 2 - Init the transaction on the objectStore
   var objectStore = transaction.objectStore("customers");
   // 3 - Get a request from the transaction for adding a new object
   var request = objectStore.add({ ssn: "123-45-6789",
                                   name: "Michel Buffa",
                                   age: 47,
                                   email: "buffa@i3s.unice.fr" });
   // The insertion was ok
   request.onsuccess = function(event) {
       console.log("Customer with ssn= " + event.target.result + "
                    added.");
   };
   // the insertion led to an error (object already in the store,
   // for example)
   request.onerror = function(event) {
       console.log("request.onerror, could not insert customer,
                    errcode = " + event.target.error.name);
   };
}

Remove data from an object store

Modifying data from an object store

Getting data from an object store

var request = objectStore.get(customerToSearch.ssn); the request.onsuccess event will hold the results:

var request = objectStore.get(customerToSearch.ssn);
   request.onsuccess = function(event) {
     console.log("Customer found" + event.target.result);
   };

Using the cursor

  function listAllCustomers() {
   var objectStore =   
     db.transaction("customers").objectStore("customers");
   objectStore.openCursor().onsuccess = function(event) {
     // we enter this callback for each object in the store
     // The result is the cursor itself
     var cursor = event.target.result;
     if (cursor) {
       alert("Name for SSN " + cursor.key + " is " +
              cursor.value.name);
       // Calling continue on the cursor will result in this callback
       // being called again if there are other objects in the store
       cursor.continue();
     } else {
       alert("No more entries!");
     }
  }; // end of onsuccess...
} // end of listAllCustomers()

  function listAllCustomersArray() {
  var objectStore =   
      db.transaction("customers").objectStore("customers");
  var customers = []; // the array of customers that will hold
                      // results
  objectStore.openCursor().onsuccess = function(event) {
    var cursor = event.target.result;
    if (cursor) {
      customers.push(cursor.value); // add a customer in the
                                    // array
      cursor.continue();
    } else {
      alert("Got all customers: " + customers);
    }
 }; // end of onsucess
} // end of listAllCustomersArray()

Getting data using an index

  var index = objectStore.index("name");
   index.get("Bill").onsuccess = function(event) {
      alert("Bill's SSN is " + event.target.result.ssn +
            " his email is " + event.target.result.email);
   };

Getting more than one result

  // normal cursor
index.openCursor().onsuccess = function(event) {
  var cursor = event.target.result;
  if (cursor) {
    // cursor.key is a name, like "Bill", and cursor.value is the
    // whole object.
    alert("Name: " + cursor.key + ", SSN: " + cursor.value.ssn + ",
           email: " + cursor.value.email);
    cursor.continue();
 }
};

  // key cursor
index.openKeyCursor().onsuccess = function(event) {
   var cursor = event.target.result;
   if (cursor) {
     // cursor.key is a name, like "Bill", and cursor.value is the
     // SSN (the key).
     // No way to directly get the rest of the stored object.
     alert("Name: " + cursor.key + ", "SSN: " + cursor.value);
     cursor.continue();
   }
};