SELECT c.cname
FROM Customers c
WHERE c.age > ALL (SELECT c2.age
 FROM Customers c2
 WHERE c2.type = 'snowboard'); 

SELECT c.cname
FROM Customers c
WHERE c.age > (SELECT MAX(c2.age)
 FROM Customers c2
 WHERE c2.type = 'snowboard')

它们对我来说看起来一样,因为MAX(c2.age)大于或等于列年龄中的所有值,如果c.age大于MAX(c2.age)那么它大于所有值.