IDBObjectStore.getKey() - Web APIs 编辑

The getKey() method of the IDBObjectStore interface returns an IDBRequest object, and, in a separate thread, returns the key selected by the specified query. This is for retrieving specific records from an object store.

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

Note:

Syntax

var request = objectStore.getKey(key);

Parameters

key

The key or key range that identifies the record to be retrieved.

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:

Example

let openRequest = indexedDB.open("telemetry");
openRequest.onsuccess = (event) => {
  let db = event.target.result;
  let store = db.transaction("netlogs").objectStore("netlogs");

  let today = new Date();
  let yesterday = new Date(today);
  yesterday.setDate(today.getDate() - 1);
  let request = store.getKey(IDBKeyRange(yesterday, today));
  request.onsuccess = (event) => {
    let when = event.target.result;
    alert("The 1st activity in last 24 hours was occurred at " + when);
  };
};

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.)