IDBDatabase：close() 方法

close()

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

// Create event handlers for both success and failure of
DBOpenRequest.onerror = (event) => {
  note.appendChild(document.createElement("li")).textContent =
    "Error loading database.";
};

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

  // store the result of opening the database in the db variable.
  db = DBOpenRequest.result;

  // now let's close the database again!
  db.close();
};