IDBObjectStore
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.
Note: This feature is available in Web Workers.
Methods
IDBObjectStore.add()
- Returns an
IDBRequest
object, and, in a separate thread, creates a structured clone of thevalue
, and stores the cloned value in the object store. This is for adding new records to an object store. IDBObjectStore.clear()
- Creates and immediately returns an
IDBRequest
object, and clears this object store in a separate thread. This is for deleting all current records out of an object store. IDBObjectStore.delete()
- returns an
IDBRequest
object, and, in a separate thread, deletes the store object selected by the specified key. This is for deleting individual records out of an object store. IDBObjectStore.get()
- Returns an
IDBRequest
object, and, in a separate thread, returns the store object store selected by the specified key. This is for retrieving specific records from an object store. IDBObjectStore.getAll()
- Returns an
IDBRequest
object retrieves all objects in the object store matching the specified parameter or all objects in the store if no parameters are given. IDBObjectStore.getAllKeys()
- Returns an
IDBRequest
object retrieves record keys for all objects in the object store matching the specified parameter or all objects in the store if no parameters are given. IDBObjectStore.createIndex()
- Creates a new index during a version upgrade, returning a new
IDBIndex
object in the connected database. IDBObjectStore.deleteIndex()
- Destroys the specified index in the connected database, used during a version upgrade.
IDBObjectStore.index()
- Opens an index from this object store after which it can, for example, be used to return a sequence of records sorted by that index using a cursor.
IDBObjectStore.put()
- Returns an
IDBRequest
object, and, in a separate thread, creates a structured clone of thevalue
, and stores the cloned value in the object store. This is for updating existing records in an object store when the transaction's mode isreadwrite
. IDBObjectStore.openCursor()
- Returns an
IDBRequest
object, and, in a separate thread, returns a newIDBCursorWithValue
object. Used for iterating through an object store by primary key with a cursor. IDBObjectStore.openKeyCursor()
- Returns an
IDBRequest
object, and, in a separate thread, returns a newIDBCursorWithValue
. Used for iterating through an object store with a key. IDBObjectStore.count()
- Returns an
IDBRequest
object, and, in a separate thread, returns the total number of records that match the provided key orIDBKeyRange
. If no arguments are provided, it returns the total number of records in the store.
Properties
IDBObjectStore.indexNames
Read only- A list of the names of indexes on objects in this object store.
IDBObjectStore.keyPath
Read only- The key path of this object store. If this attribute is
null
, the application must provide a key for each modification operation. IDBObjectStore.name
- The name of this object store.
IDBObjectStore.transaction
Read only- The
IDBTransaction
object to which this object store belongs. IDBObjectStore.autoIncrement
Read only- The value of the auto increment flag for this object store.
Example
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.)
JavaScript
Copy Code
// Let us open our database var DBOpenRequest = window.indexedDB.open("toDoList", 4); DBOpenRequest.onsuccess = function(event) { note.innerHTML += '<li>Database initialised.</li>'; // store the result of opening the database in the db variable. db = DBOpenRequest.result; }; // 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 = function(event) { var db = event.target.result; db.onerror = function(event) { note.innerHTML += '<li>Error loading database.</li>'; }; // Create an objectStore for this database var 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.innerHTML += '<li>Object store created.</li>'; }; // Create a new item to add in to the object store var newItem = [ { taskTitle: "Walk dog", hours: 19, minutes: 30, day: 24, month: 'December', year: 2013, notified: "no" } ]; // open a read/write db transaction, ready for adding the data var transaction = db.transaction(["toDoList"], "readwrite"); // report on the success of opening the transaction transaction.oncomplete = function(event) { note.innerHTML += '<li>Transaction opened for task addition.</li>'; }; transaction.onerror = function(event) { note.innerHTML += '<li>Transaction not opened due to error. Duplicate items not allowed.</li>'; }; // create an object store on the transaction var objectStore = transaction.objectStore("toDoList"); // add our newItem object to the object store var objectStoreRequest = objectStore.add(newItem[0]); objectStoreRequest.onsuccess = function(event) { note.innerHTML += '<li>New item added to database.</li>'; }
Specifications
Specification | Status | Comment |
---|---|---|
Indexed Database API The definition of 'IDBObjectStore' in that specification. |
Recommendation |
Browser compatibility
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
---|---|---|---|---|---|
Basic support | 23webkit 24 |
10 moz 16.0 (16.0) |
10, partial | 15 | 7.1 |
Available in workers | (Yes) | 37.0 (37.0) | ? | (Yes) | ? |
name setter available |
? | 49 (49) | ? | ? | ? |
Feature | Android | Android Webview | Firefox Mobile (Gecko) | Firefox OS | IE Phone | Opera Mobile | Safari Mobile | Chrome for Android |
---|---|---|---|---|---|---|---|---|
Basic support | 4.4 | (Yes) | 22.0 (22.0) | 1.0.1 | 10 | 22 | 8 | (Yes) |
Available in workers | No support | (Yes) | 37.0 (37.0) | (Yes) | ? | (Yes) | ? | (Yes) |
name setter available |
? | ? | 49.0 (49) | ? | ? | ? | ? | ? |
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.)
License
© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-us/docs/web/api/idbobjectstore