title: SQL Server Database is not updated via C# Code
body: <p>I am performing record update operation . my update operation is happening fine but database is not updating values . below is update code. </p>
  
  <pre><code>        SupPartEntityVal supplypart = new SupPartEntityVal();
  
          String sNum = sNumText.Text;
          String sName = sNameText.Text;
          String sStatus = sText.Text;
          String sCity = cText.Text;
          int rowIndex = int.Parse(rIndex.Text);
  
          ObjectQuery&lt;S&gt; supply = supplypart.S;
          var query =
          from product in supply
          select new { product.SNUM, product.SNAME, product.STATUS, product.CITY };
          S sup = supplypart.S.Single(product =&gt; product.SNUM == sNum);
          sup.SNAME = sName; sup.STATUS = short.Parse(sStatus); sup.CITY = sCity;
  
          this.supplypart.SaveChanges();
  </code></pre>
  
  <ol>
  <li>After making changes, I can see updated value on UI</li>
  <li>After I close an application, reopen again I can see updated value on UI </li>
  <li>Close Visual studio, reopen the application and run it again. </li>
  <li>I do not see changes in database. </li>
  </ol>
  
  <p>am i missing something???  </p>