title: bulkCopy.WriteToServer() not throwing exception when no data is copied
body: <p>I'm trying to copy a <code>DataTable</code> into a destination table on Sql Server. I use the following code. I know that <code>bulkCopy.WriteToServer()</code> is an atomic (all-or-nothing) function. But when nothing has been copied, I would like to know! </p>
  
  <pre><code>try
  {
      using (SqlBulkCopy bulkCopy = new SqlBulkCopy(sqlConn.ConnectionString, SqlBulkCopyOptions.KeepIdentity | SqlBulkCopyOptions.UseInternalTransaction))
      {
          bulkCopy.DestinationTableName = "MyDestinationTable";
          bulkCopy.WriteToServer(dt);
          convertSuccess = true;
      }
  }
  catch
  {
      convertSuccess = false;
  }
  </code></pre>
  
  <p>I have seen the case that nothing was copied into "MyDestinationTable" but I was unaware of it because my <code>convertSuccess</code> flag returned <code>true</code>. Is there a way to know if the bulkCopy has done its job?</p>