题解 | #浙江大学用户题目回答情况#

# 子查询
# select device_id,question_id,result 
# from question_practice_detail 
# where device_id=(
#     select device_id 
#     from user_profile
#     where university="浙江大学"
# );


# 连接查询
# select question_practice_detail.device_id,question_id,result
# from question_practice_detail, user_profile 
# where question_practice_detail.device_id = user_profile.device_id 
# and user_profile.university = '浙江大学'


#内连接查询
select question_practice_detail.device_id,question_id,result
from question_practice_detail inner join user_profile 
on question_practice_detail.device_id = user_profile.device_id 
and user_profile.university = '浙江大学'