从php中获取mysql中列数组的数据

I have a database like this:

id   |   data
1        a:3:{s:12:"question1";s:1:"a";s:7:"question2";s:1:"b";}
2        a:3:{s:12:"question1";s:1:"c";s:7:"question2";s:1:"d";}

And I need to get the values of "question1". Any idea how can i get it?

Thanks guys