title: Still include rows where no matching values found
body: <p>I have got 2 tables, one with the columns:</p>
  <ul>
  <li>ItemId</li>
  <li>Number</li>
  <li>Title</li>
  <li>CreatedDate</li>
  <li>LastModifiedDate</li>
  </ul>
  <p>And the other one with the columns:</p>
  <ul>
  <li>ItemId</li>
  <li>Title</li>
  <li>ItemTitle</li>
  </ul>
  <p>What I am trying to do is create a new datatable that clones the first one with the column &quot;Function&quot; added, the values for this column will come from the ItemTitle column from the 2nd dataTable.</p>
  <p>I am doing this like so:</p>
  <pre><code>DataTable test = dtFinal.Clone();
  test.Columns.Add(&quot;Function&quot;);
  
  foreach (DataRow row in dtFinal.Rows)
  {
      DataRow[] FunctionData = customPropertiesTable.Select(string.Format(&quot;ItemId='{0}' AND Title ='Function'&quot;, Convert.ToString(row[&quot;ItemId&quot;])));
  
      if (FunctionData != null &amp;&amp; FunctionData.Length &gt; 0)
      {
          string detail = FunctionData[0][&quot;ItemTitle&quot;].ToString();
          var lst = row.ItemArray.ToList();
          lst.Add(detail);
          test.Rows.Add(lst.ToArray());
  
      }
  
  }
  </code></pre>
  <p>Now this does work but it means that the new table will only show rows where that condition is met, what I would like to do is have it that the new table will still include the rows where the condition was not met so I could end with something like:</p>
  <p><a href="https://i.stack.imgur.com/sQMCd.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/sQMCd.png" alt="enter image description here" /></a></p>
  <p>Where the function value of the row could be blank if the condition wasn't met. How could I update what I have done to do this?</p>