SQL25题解 | #查找山东大学或者性别为男生的信息#

#不去重union all,WHERE和UNION和自动去重
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';