title: Convert all data in SQL Server to unicode
body: <p>My database table string columns are <code>nvarchar</code>. </p>
  
  <p>But when I insert my data using application, I forgot to add the <code>N'</code> prefix. So the display is not UTF-8 on web. This causes lot of problems.</p>
  
  <p>How do I use some T-SQL command to replace all existing tables and all string columns <strong>type</strong> and <strong>data</strong> to UTF-8?</p>