学会了 union all是可以不去重的!! 感谢大佬
select
device_id, gender, age, gpa
from user_profile
where university='山东大学'
union all
select
device_id, gender, age, gpa
from user_profile
where gender='male'

学会了 union all是可以不去重的!! 感谢大佬
select
device_id, gender, age, gpa
from user_profile
where university='山东大学'
union all
select
device_id, gender, age, gpa
from user_profile
where gender='male'