title: Find a name that is not used in another table
body: <p>In my <strong>Role.php</strong> I have the following.</p>
  
  <pre class="lang-php prettyprint-override"><code>class Role extends Model
  {
      protected $fillable = [
          'name'
      ];
  
      public function users()
      {
          return $this-&gt;belongsToMany(User::class)-&gt;withTimestamps();
      }
  }
  </code></pre>
  
  <p>I tried a query like this:
  </p>
  
  <pre><code>$leaders = Role::where('name','leader')-&gt;with('users')-&gt;first();
  </code></pre>
  
  <p>I got two names by querying this:</p>
  
  <pre><code>1-&gt;Tanvir AHmed
  2-&gt;Nayeem
  </code></pre>
  
  <p>And, I have another table named <code>teams</code> and it has a column named <code>leader_name</code> and data like the following:</p>
  
  <pre><code>teams.leader_name
  Tanvir AHmed
  </code></pre>
  
  <p>Now I want to fetch the names which are not contained in the teams' table. Like, in this case, Tanvir is present and Nayeem is not. How can I fetch this name(Nayeem)?  </p>