IDBObjectStore.getAll() - Web APIs 编辑

The getAll() method of the IDBObjectStore interface returns an IDBRequest object containing all objects in the object store matching the specified parameter or all objects in the store if no parameters are given.

If a value is successfully found, then a structured clone of it is created and set as the result of the request object.

This method produces the same result for:

• a record that doesn't exist in the database
• a record that has an undefined value

To tell these situations apart, you either call

1. the openCursor() method with the same key. That method provides a cursor if the record exists, and no cursor if it does not.
2. the count() method with the same key, which will return 1 if the row exists and 0 if it doesn't.

Syntax

var request = objectStore.getAll();
var request = objectStore.getAll(query);
var request = objectStore.getAll(query, count);

Parameters

query Optional

A key or IDBKeyRange to be queried. If nothing is passed, this will default to a key range that selects all the records in this object store.

count Optional

Specifies the number of values to return if more than one is found. If it is lower than 0 or greater than 232-1 a TypeError exception will be thrown.

Return value

An IDBRequest object on which subsequent events related to this operation are fired.

Exceptions

This method may raise a DOMException of one of the following types:

A TypeError exception is thrown if the count parameter is not between 0 and 232-1 included.

Specifications

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.)