题解 | #用where过滤空值练习#
用where过滤空值练习
http://www.nowcoder.com/practice/08c9846a423540319eea4be44e339e35
(1)
select device_id, gender, age, university from user_profile where not isnull(age)
(2)
select device_id, gender, age, university from user_profile where isnull(age) = 0