query: SELECT country FROM stadium EXCEPT SELECT country FROM stadium WHERE opening_year  >  2006
question: Which country them ain't having the where have been a-opened 2006 stadium?
query_toks: SELECT country FROM stadium EXCEPT SELECT country FROM stadium WHERE opening_year > 2006
query_toks_no_value: select country from stadium except select country from stadium where opening_year > value
question_toks: Which country them ain't having the where have been a-opened 2006 stadium?