I tried, honestly, I tried ... but regular expressions hate me!!!! argggh

Lets say $url = 'http://www.domain.com/data/tt0317219/&sa=X&oi=realestate&ii=6" class="data"';

I want to use a regular expression to change $url to 'http://www.domain.com/data/tt0317219';
(everthing after /data/ changes per link)

Can someone be kind enough to help me write the expression?

You tried before asking; good. But what did you try? What were the results?