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
Instance 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.
Instance 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.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. IDBObjectStore.createIndex()
-
Creates a new index during a version upgrade, returning a new
IDBIndex
object in the connected database. 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.deleteIndex()
-
Destroys the specified index in the connected database, used during a version upgrade.
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.getKey()
-
Returns an
IDBRequest
object, and, in a separate thread retrieves and returns the record key for the object in the object stored matching the specified parameter. 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.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.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 newIDBCursor
. Used for iterating through an object store with a key. 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
.
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).
js
// Let us open our database
const DBOpenRequest = window.indexedDB.open("toDoList", 4);
DBOpenRequest.onsuccess = (event) => {
note.innerHTML += "<li>Database initialized.</li>";
// store the result of opening the database in db.
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 = (event) => {
const db = event.target.result;
db.onerror = (event) => {
note.innerHTML += "<li>Error loading database.</li>";
};
// Create an objectStore for this database
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.innerHTML += "<li>Object store created.</li>";
};
// Create a new item to add in to the object store
const 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
const transaction = db.transaction(["toDoList"], "readwrite");
// report on the success of the transaction completing, when everything is done
transaction.oncomplete = (event) => {
note.innerHTML += "<li>Transaction completed.</li>";
};
transaction.onerror = (event) => {
note.innerHTML +=
"<li>Transaction not opened due to error. Duplicate items not allowed.</li>";
};
// create an object store on the transaction
const objectStore = transaction.objectStore("toDoList");
// make a request to add our newItem object to the object store
const objectStoreRequest = objectStore.add(newItem[0]);
objectStoreRequest.onsuccess = (event) => {
note.innerHTML += "<li>Request successful .</li>";
};
Specifications
Specification |
---|
Indexed Database API 3.0 # object-store-interface |
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 the example live).