PHP + SQL Server - How to set charset for connection?

Client charset is necessary but not sufficient:

ini_set('mssql.charset', 'UTF-8');

I searched for two days how to insert UTF-8 data (from web forms) into MSSQL 2008 through PHP. I read everywhere that you can't, you need to convert to UCS2 first (like cypher's solution recommends). On Windows SQLSRV said to be a good solution, which I couldn't try, since I am developing on Mac OSX.

However, FreeTDS manual (what PHP mssql uses on OSX) says to add a letter "N" before the opening quote:

mssql_query("INSERT INTO table (nvarcharField) VALUES (N'űáúőűá球最大的采购批发平台')", +xon);

According to this discussion, N character tells the server to convert to Unicode. https://softwareengineering.stackexchange.com/questions/155859/why-do-we-need-to-put-n-before-strings-in-microsoft-sql-server

I had the same problem and ini_set('mssql.charset', 'utf-8') did not work for me. However, it worked in uppercase:

ini_set('mssql.charset', 'UTF-8');