files/en-us/web/api/idbdatabase/index.md
{{APIRef("IndexedDB")}} {{AvailableInWorkers}}
The IDBDatabase interface of the IndexedDB API provides a connection to a database; you can use an IDBDatabase object to open a transaction on your database then create, manipulate, and delete objects (data) in that database. The interface provides the only way to get and manage versions of the database.
[!NOTE] Everything you do in IndexedDB always happens in the context of a transaction, representing interactions with data in the database. All objects in IndexedDB — including object stores, indexes, and cursors — are tied to a particular transaction. Thus, you cannot execute commands, access data, or open anything outside of a transaction.
{{InheritanceDiagram}}
Inherits from: EventTarget
Listen to these events using addEventListener() or by assigning an event listener to the oneventname property of this interface.
The following events are available to IDBDatabase via event bubbling from {{domxref("IDBTransaction")}}:
IDBTransaction abort
IDBTransaction error
In the following code snippet, we open a database asynchronously ({{domxref("IDBFactory")}}), handle success and error cases, and create a new object store in the case that an upgrade is needed (IDBDatabase). For a complete working example, see our To-do Notifications app (view example live).
// Let us open our database
const DBOpenRequest = window.indexedDB.open("toDoList", 4);
// these two event handlers act on the IDBDatabase object,
// when the database is opened successfully, or not
DBOpenRequest.onerror = (event) => {
note.appendChild(document.createElement("li")).textContent =
"Error loading database.";
};
DBOpenRequest.onsuccess = (event) => {
node.appendChild(document.createElement("li")).textContent =
"Database initialized.";
// store the result of opening the database in the db
// variable. This is used a lot later on
db = DBOpenRequest.result;
// Run the displayData() function to populate the task
// list with all the to-do list data already in the IDB
displayData();
};
// This event handles the event whereby a new version of
// the database needs to be created Either one has not
// been created before, or a new version number has been
// submitted via the window.indexedDB.open line above
DBOpenRequest.onupgradeneeded = (event) => {
const db = event.target.result;
db.onerror = (event) => {
note.appendChild(document.createElement("li")).textContent =
"Error loading database.";
};
// Create an objectStore for this database using
// IDBDatabase.createObjectStore
const objectStore = db.createObjectStore("toDoList", {
keyPath: "taskTitle",
});
// define what data items the objectStore will contain
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.appendChild(document.createElement("li")).textContent =
"Object store created.";
};
This next line opens up a transaction on the Database, then opens an object store that we can then manipulate the data inside of.
const objectStore = db
.transaction("toDoList", "readwrite")
.objectStore("toDoList");
{{Specifications}}
{{Compat}}