IDBFactory: open() method

{{APIRef("IndexedDB")}}  {{AvailableInWorkers}} 

The open() method of the {{domxref("IDBFactory")}}  interface requests opening a connection to a database.

The method returns an {{domxref("IDBOpenDBRequest")}}  object immediately, and performs the open operation asynchronously. If the operation is successful, a success event is fired on the request object that is returned from this method, with its result attribute set to the new {{domxref("IDBDatabase")}}  object for the connection.

May trigger upgradeneeded, blocked or versionchange events.

Syntax

open(name)
open(name, version)

Parameters

• name
  • : The name of the database.
• version {{optional_inline}} 
  • : Optional. The version to open the database with. If the version is not provided and the database exists, then a connection to the database will be opened without changing its version. If the version is not provided and the database does not exist, then it will be created with version 1.

Return value

A {{domxref("IDBOpenDBRequest")}}  object on which subsequent events related to this request are fired.

If the operation is successful, the value of the request’s {{domxref("IDBRequest.result", "result")}}  property is a {{domxref("IDBDatabase")}}  object representing the connection to the database.

Exceptions

• {{jsxref("TypeError")}} 
  • : Thrown if the value of version is not a number greater than zero.

Examples

Example of calling open with the current specification’s version parameter:

const request = window.indexedDB.open("toDoList", 4);

In the following code snippet, we make a request to open a database, and include handlers for the success and error cases. For a full working example, see our To-do Notifications app (View the example live).

const note = document.querySelector("ul");

// Let us open version 4 of our database
const DBOpenRequest = window.indexedDB.open("toDoList", 4);

// these two event handlers act on the database being opened
// successfully, or not
DBOpenRequest.onerror = (event) => {
  note.appendChild(document.createElement("li")).textContent =
    "Error loading database.";
};

DBOpenRequest.onsuccess = (event) => {
  note.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, for opening
  // transactions and suchlike.
  db = DBOpenRequest.result;
};

Specifications

{{Specifications}} 

Browser compatibility

{{Compat}} 

See also

• Using IndexedDB
• Browser storage quotas and eviction criteria.
• Starting transactions: {{domxref("IDBDatabase")}} 
• Using transactions: {{domxref("IDBTransaction")}} 
• Setting a range of keys: {{domxref("IDBKeyRange")}} 
• Retrieving and making changes to your data: {{domxref("IDBObjectStore")}} 
• Using cursors: {{domxref("IDBCursor")}} 
• Reference example: To-do Notifications (View the example live).