select s.sname,count(*)
from suppliers s,parts p,catalog c
where p.pid = c.pid and c.sid = s.sid
group by s.sname,s.sid
having every (p.color = 'green')
select s.sname,max(c.cost)
from suppliers s,s.sid
having some (p.color = 'green') and some (p.color = 'red')
当我执行以上两个查询时，它显示缺少右括号。