Query strings in Canoncials URLs

[BostonWright]

Video on my site all resides at www.mydomain.com/video in a player that does not assign unique URLs for each video. We may be able to rewrite the URLs to include a unique identifier found in the video's metadata (www.mydomain.com/video/?bctid=17769780). If I did this, how would it impact the canonical URL? Do the SEs accept canonicals with query strings? What if I only changed the canonical URL and did not change the video's URL? Would that be a problem?

[NakulGoyal]

If your video URL is www.mydomain.com/video/?bctid=1776978, then your canonical tag should be this as well. Canonical Tag will essentially help you get rid of possible duplicate content issue when the CMS generates URLs like: www.mydomain.com/video/?bctid=17769780&whatever=here www.mydomain.com/video/?bctid=17769780&display=fullscreen and so on. Does that help. ? in the Canonical Tag is not a problem.

[BostonWright]

Would it be a problem if I used a canonical with a query string but did not change the video URL? A new tracking system we'd like to use is based off of the canonical URL. So for tracking reasons we want to append the canonical URL with the video's unique ID. Making this change is easy, but to change the actual video URLs will require a bit more dev work. Is this going to cause problems?

[irvingw]

the canonical tag must go to a valid url that is unique per video. you need to update the canonical and url at the same time.