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'
union all 将两个查询结果合并,不删除重复记录
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'
union all 将两个查询结果合并,不删除重复记录