The open()
method of the IDBFactory
interface requests opening a connection to a database.
The method returns an 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
IDBDatabase
object for the connection.
If an error occurs while the database connection is being opened, then an error event is fired on the request object returned from this method.
May trigger upgradeneeded
, blocked
or
versionchange
events.
Note:
This feature is available in Web Workers.Syntax
For the current standard:
var IDBOpenDBRequest = indexedDB.open(name);
var IDBOpenDBRequest = indexedDB.open(name, version);
Parameters
- name
- The name of the database.
- version Optional
- 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
.
Experimental Gecko options object
- options (version and storage) Optional
- In Gecko, since version 26, you can include
a non-standard
options
object as a parameter ofIDBFactory.open
that contains theversion
number of the database, plus a storage value that specifies whether you want to usepersistent
ortemporary
storage.Warning: Thestorage
attribute is deprecated and will soon be removed from Gecko. You should useStorageManager.persist()
to get persistent storage instead.
Note: You can find out more information on the different available storage types, and how Firefox handles client-side data storage, at Browser storage limits and eviction criteria.
Return value
A IDBOpenDBRequest
object on which subsequent events related to this
request are fired.
Exceptions
This method may raise a DOMException
of the following types:
Exception | Description |
---|---|
TypeError |
The value of version is zero or a negative number or not a number. |
Example
Example of calling open
with the current specification's
version
parameter:
var 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 example live.)
var note = document.querySelector("ul");
// In the following line, you should include the prefixes
// of implementations you want to test.
window.indexedDB = window.indexedDB || window.mozIndexedDB || window.webkitIndexedDB || window.msIndexedDB;
// DON'T use "var indexedDB = ..." if you're not in a function.
// Moreover, you may need references to some window.IDB* objects:
window.IDBTransaction = window.IDBTransaction || window.webkitIDBTransaction || window.msIDBTransaction;
window.IDBKeyRange = window.IDBKeyRange || window.webkitIDBKeyRange || window.msIDBKeyRange;
// (Mozilla has never prefixed these objects, so we don't
// need window.mozIDB*)
// Let us open version 4 of our database
var DBOpenRequest = window.indexedDB.open("toDoList", 4);
// these two event handlers act on the database being opened
// successfully, or not
DBOpenRequest.onerror = function(event) {
note.innerHTML += '<li>Error loading database.</li>';
};
DBOpenRequest.onsuccess = function(event) {
note.innerHTML += '<li>Database initialised.</li>';
// 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
Specification | Status | Comment |
---|---|---|
Indexed Database API 2.0 The definition of 'open()' in that specification. |
Recommendation | |
Indexed Database API 2.0 The definition of 'open()' in that specification. |
Recommendation |
Browser compatibility
BCD tables only load in the browser
See also
- Using IndexedDB
- Starting transactions:
IDBDatabase
- Using transactions:
IDBTransaction
- Setting a range of keys:
IDBKeyRange
- Retrieving and making changes to your data:
IDBObjectStore
- Using cursors:
IDBCursor
- Reference example: To-do Notifications (view example live.)