title: Change datatype varchar to nvarchar in existing SQL Server 2005 database. Any issues?
body: <p>I need to change column datatypes in a database table from <code>varchar</code> to <code>nvarchar</code> in order to support Chinese characters (currently, the <code>varchar</code> fields that have these characters are only showing question marks). </p>
  
  <p>I know how to change the values, but I want to see if it's safe to do so. Is there anything to look out for before I do the changing? Thanks!</p>