          await DB.Update&lt;Author&gt;()
                            .Match(_ =&gt; true)
                            .Modify(x =&gt; x.FullName, a.fullname)
                            .ExecuteAsync();
                });
    }
}
</code></pre>
<p>if your collection has many thousands of documents, the above code will be less efficient. below is another more efficient way to achieve the same result using a single mongodb command if your server version is v4.2 or newer.</p>
<pre><code class="lang-csharp">pu