web api interface

IDBDatabase

Available in workers

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.

Instance properties

name Read only
- : A string that contains the name of the connected database.
version Read only
- : A 64-bit integer that contains the version of the connected database. When a database is first created, this attribute is an empty string.
objectStoreNames Read only
- : A DOMStringList that contains a list of the names of the object stores currently in the connected database.

Instance methods

Inherits from: EventTarget

close()
- : Returns immediately and closes the connection to a database in a separate thread.
createObjectStore()
- : Creates and returns a new object store or index.
deleteObjectStore()
- : Destroys the object store with the given name in the connected database, along with any indexes that reference it.
transaction()
- : Immediately returns a transaction object (IDBTransaction) containing the objectStore method, which you can use to access your object store. Runs in a separate thread.

Events

Listen to these events using addEventListener() or by assigning an event listener to the oneventname property of this interface.

close
- : An event fired when the database connection is unexpectedly closed.
versionchange
- : An event fired when a database structure change was requested.

The following events are available to IDBDatabase via event bubbling from IDBTransaction:

IDBTransaction abort
- : An event fired when a transaction is aborted.
IDBTransaction error
- : An event fired when a request returns an error and the event bubbles up to the connection object.

Example

In the following code snippet, we open a database asynchronously (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

SpecificationsStandards references are available on the canonical MDN page.

Browser compatibility

Browser compatibilityCompatibility data is available on the canonical MDN page.