title: Update problems in Entity Framework
body: <p>I want update my table with two conditions :</p>
  
  <pre><code>Type == "پیش ثبت نام" &amp;&amp; Approved == false
  </code></pre>
  
  <p>and I use this code :</p>
  
  <pre><code>using (NoavaranModel.NoavaranEntities1 db=new NoavaranModel.NoavaranEntities1())
  {
      var query = db.Students.Where(p =&gt; p.Type == "پیش ثبت نام" &amp;&amp; p.Approved == false).Single();
      query.IsRecivedSMS = true;
  
      db.SaveChanges();
  }
  </code></pre>
  
  <p>but it's not working. Just updates one recode in db. How can I update all rows with above conditions in Entity Framework?</p>