题解 | #用where过滤空值练习#
用where过滤空值练习
https://www.nowcoder.com/practice/08c9846a423540319eea4be44e339e35
解题思路
where过滤空值,注意不能用等于号,因为null表示不确定,不和任何值相等,只能用is来比较
代码实现
select device_id, gender, age, university from user_profile where age is not NULL
用where过滤空值练习
https://www.nowcoder.com/practice/08c9846a423540319eea4be44e339e35
where过滤空值,注意不能用等于号,因为null表示不确定,不和任何值相等,只能用is来比较
select device_id, gender, age, university from user_profile where age is not NULL
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