title: Getting the error "cannot add an entity that already exists." while inserting a table's value in to DB without procedure
body: <p>I am inserting a list of records to the DB table with Linq to sql like this:</p>
  
  <pre><code>//my DataContext Class
   using (VTMMedicalDBDataContext objVTMMedicalDBDataContext = new VTMMedicalDBDataContext())
   {
       ReadOnlyCollection&lt;TimeZoneInfo&gt; objTimeZones = null;
  
       objTimeZones = TimeZoneInfo.GetSystemTimeZones();
  
       if (objTimeZones.Count &gt; 0)
       {
           //List&lt;TimeZoneMaster&gt; listTimeZones = new List&lt;TimeZoneMaster&gt;();
           TimeZoneMaster objTimeZoneMaster = new TimeZoneMaster();
  
           foreach (var timezone in objTimeZones.ToList())
           {
  
               objTimeZoneMaster.TimeZoneName = timezone.DisplayName;
  
               var localName = timezone.DisplayName;
  
               objTimeZoneMaster.TimeZoneOffsetInMinutes = Convert.ToInt32(timezone.BaseUtcOffset.TotalMinutes);                      
  
  
               objVTMMedicalDBDataContext.TimeZoneMasters.InsertOnSubmit(objTimeZoneMaster);
               objVTMMedicalDBDataContext.SubmitChanges();
  
  
           }
  
       }
  }   
  </code></pre>
  
  <p>I have a primary key but I have already made it as AutoGeneratd as true in DBML Nullable as false.Still I am not able to get rid of it...Please suggest some way around.</p>