Unicode String Constants in SQL Server Require N Prefix

When dealing with Unicode string constants in SQL Server you must precede all Unicode strings with a capital letter N, as documented in the SQL Server Books Online topic "Using Unicode Data". The "N" prefix stands for National Language in the SQL-92 standard, and must be uppercase. If you do not prefix a Unicode string constant with N, SQL Server will convert it to the non-Unicode code page of the current database before it uses the string.

"INSERT INTO mytable VALUES (100, N'string with Chinese chars')"

Please see: http://support.microsoft.com/default.aspx?scid=kb;EN-US;Q239530