The IDBObjectStore
interface of the IndexedDB API represents an object store in a database. Records within an object store are sorted according to their keys. This sorting enables fast insertion, look-up, and ordered retrieval.
This example shows a variety of different uses of object stores, from updating the data structure with IDBObjectStore.createIndex
inside an onupgradeneeded
function, to adding a new item to our object store with IDBObjectStore.add
. For a full working example, see our To-do Notifications app (view example live.)
var DBOpenRequest = window.indexedDB.open("toDoList", 4);
DBOpenRequest.onsuccess = function(event) {
note.innerHTML += '<li>Database initialized.</li>';
db = DBOpenRequest.result;
};
DBOpenRequest.onupgradeneeded = function(event) {
var db = event.target.result;
db.onerror = function(event) {
note.innerHTML += '<li>Error loading database.</li>';
};
var objectStore = db.createObjectStore("toDoList", { keyPath: "taskTitle" });
objectStore.createIndex("hours", "hours", { unique: false });
objectStore.createIndex("minutes", "minutes", { unique: false });
objectStore.createIndex("day", "day", { unique: false });
objectStore.createIndex("month", "month", { unique: false });
objectStore.createIndex("year", "year", { unique: false });
objectStore.createIndex("notified", "notified", { unique: false });
note.innerHTML += '<li>Object store created.</li>';
};
var newItem = [
{ taskTitle: "Walk dog", hours: 19, minutes: 30, day: 24, month: 'December', year: 2013, notified: "no" }
];
var transaction = db.transaction(["toDoList"], "readwrite");
transaction.oncomplete = function(event) {
note.innerHTML += '<li>Transaction completed.</li>';
};
transaction.onerror = function(event) {
note.innerHTML += '<li>Transaction not opened due to error. Duplicate items not allowed.</li>';
};
var objectStore = transaction.objectStore("toDoList");
var objectStoreRequest = objectStore.add(newItem[0]);
objectStoreRequest.onsuccess = function(event) {
note.innerHTML += '<li>Request successful .</li>';
}