title: Nvarchar and text are incompatible in the add operator
body: <p>With SQL Server 2008, I'd like to add a variable (<code>@wfID</code>) into a text, like below:</p>
  
  <pre><code> DECLARE @wfID uniqueidentifier
   SET @wfID = NEWID()
  
  '&lt;META http-equiv="Content-Type" content="text/html; " /&gt;  &lt;br&gt;&lt;input type="button"
      value="" onclick="window.open(&amp;quot;http://localhost/TestWeb2/Test_Look.aspx?Test_ID='
      + convert(nvarchar, @wfID)
      + '&amp;quot;);" /&gt;&lt;/br&gt;',
  </code></pre>
  
  <p>So, I'd like to add the <code>@wfID</code> to the text but it always says </p>
  
  <blockquote>
    <p>The data types nvarchar and text are incompatible in the add operator.</p>
  </blockquote>
  
  <p>I tried converting everything into nvarchar, but then I got this:</p>
  
  <blockquote>
    <p>Arithmetic overflow error converting expression to data type nvarchar.</p>
  </blockquote>
  
  <p>Any suggestions?</p>