题解 | #用where过滤空值练习#

判断某列不为空： 1、 is not null

select device_id,gender,age,university
from user_profile
where age is not null;

2、 not...is null

select device_id,gender,age,university
from user_profile
where not age is null;

3、where age

select device_id,gender,age,university
from user_profile
where age;