IDBObjectStore: get() method

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

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

[!NOTE] This method produces the same result for: a) a record that doesn't exist in the database and b) a record that has an undefined value. To tell these situations apart, call the openCursor() method with the same key. That method provides a cursor if the record exists, and no cursor if it does not.

Syntax

js-nolint

get(key)

Parameters

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

Return value

An {{domxref("IDBRequest")}} object on which subsequent events related to this operation are fired.

If the operation is successful, the value of the request's {{domxref("IDBRequest.result", "result")}} property is the value of the first record matching the given key or key range.

Exceptions

This method may raise a {{domxref("DOMException")}} of one of the following types:

TransactionInactiveError {{domxref("DOMException")}}
- : Thrown if this {{domxref("IDBObjectStore")}}'s transaction is inactive.
DataError {{domxref("DOMException")}}
- : Thrown if key or key range provided contains an invalid key.
InvalidStateError {{domxref("DOMException")}}
- : Thrown if the {{domxref("IDBObjectStore")}} has been deleted or removed.

Examples

In the following code snippet, we open a read/write transaction on our database and get one specific record from object store using get() — a sample record with the key "Walk dog". Once this data object is retrieved, you could then update it using normal JavaScript, then put it back into the database using a {{domxref("IDBObjectStore.put", "put()")}} operation. For a full working example, see our To-do Notifications app (view example live).

// Let us open our database
const DBOpenRequest = window.indexedDB.open("toDoList", 4);

DBOpenRequest.onsuccess = (event) => {
  note.appendChild(document.createElement("li")).textContent =
    "Database initialized.";

  // store the result of opening the database in the db variable.
  // This is used a lot below
  db = DBOpenRequest.result;

  // Run the getData() function to get the data from the database
  getData();
};

function getData() {
  // open a read/write db transaction, ready for retrieving the data
  const transaction = db.transaction(["toDoList"], "readwrite");

  // report on the success of the transaction completing, when everything is done
  transaction.oncomplete = (event) => {
    note.appendChild(document.createElement("li")).textContent =
      "Transaction completed.";
  };

  transaction.onerror = (event) => {
    note.appendChild(document.createElement("li")).textContent =
      `Transaction not opened due to error: ${transaction.error}`;
  };

  // create an object store on the transaction
  const objectStore = transaction.objectStore("toDoList");

  // Make a request to get a record by key from the object store
  const objectStoreRequest = objectStore.get("Walk dog");

  objectStoreRequest.onsuccess = (event) => {
    // report the success of our request
    note.appendChild(document.createElement("li")).textContent =
      "Request successful.";

    const myRecord = objectStoreRequest.result;
  };
}

Syntax

Parameters

Return value

Exceptions

Examples

Specifications

Browser compatibility

See also