The International Social Survey Program (ISSP) has conducted "national identity" surveys in multiple countries in 1997, 2003, and 2013. I do not think the 2013 data are available to the public yet. I have analyzed the earlier data, and you can see one paper based on that in my publication list: See my "Pride and Prejudice" paper from 2007, available online here. You can find some information about the ISSP at this site (and the data are made available by GESIS): http://www.issp.org/page.php?pageId=4
Correction, the first National Identity survey was in 1995, not 1997. Here's a link to the GESIS website, where you can find (and download) data and documentation: http://www.gesis.org/en/issp