Question

在SQL的嵌套查询中，如何区分谓词ANY和ALL，请用实例进行说明。

麻烦举一下例子呀。

Answer 1

any 是任意一个
all 是所有

比如
select * from student where 班级='01' and age > all (select age from student where 班级='02');

就是说，查询出01班中，年龄大于 02班所有人 的 同学
相当于
select * from student where 班级='01' and age > (select max(age) from student where 班级='02');

而
select * from student where 班级='01' and age > any (select age from student where 班级='02');

就是说，查询出01班中，年龄大于 02班任意一个 的 同学
相当于
select * from student where 班级='01' and age > (select min(age) from student where 班级='02');