【牛客刷题--SQL篇】多表查询组合查询SQL25 查找山东大学或者性别为男生的信息

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文章目录

一、多表查询

1、组合查询

1.1、SQL25 查找山东大学或者性别为男生的信息

• 描述 题目：现在运营想要分别查看学校为山东大学或者性别为男性的用户的device_id、gender、age和gpa数据，请取出相应结果，结果不去重。
• 示例1

输入：
drop table if exists

user_profile

;
drop table if exists

question_practice_detail

;
CREATE TABLE

user_profile

(

id

int NOT NULL,

device_id

int NOT NULL,

gender

varchar(14) NOT NULL,

age

int ,

university

varchar(32) NOT NULL,

gpa

float,

active_days_within_30

int ,

question_cnt

int ,

answer_cnt

int
);
CREATE TABLE

question_practice_detail

(

id

int NOT NULL,

device_id

int NOT NULL,

question_id

int NOT NULL,

result

varchar(32) NOT NULL
);
CREATE TABLE

question_detail

(

id

int NOT NULL,

question_id

int NOT NULL,

difficult_level

varchar(32) NOT NULL
);

INSERT INTO user_profile VALUES(1,2138,‘male’,21,‘北京大学’,3.4,7,2,12);
INSERT INTO user_profile VALUES(2,3214,‘male’,null,‘复旦大学’,4.0,15,5,25);
INSERT INTO user_profile VALUES(3,6543,‘female’,20,‘北京大学’,3.2,12,3,30);
INSERT INTO user_profile VALUES(4,2315,‘female’,23,‘浙江大学’,3.6,5,1,2);
INSERT INTO user_profile VALUES(5,5432,‘male’,25,‘山东大学’,3.8,20,15,70);
INSERT INTO user_profile VALUES(6,2131,‘male’,28,‘山东大学’,3.3,15,7,13);
INSERT INTO user_profile VALUES(7,4321,‘male’,28,‘复旦大学’,3.6,9,6,52);
INSERT INTO question_practice_detail VALUES(1,2138,111,‘wrong’);
INSERT INTO question_practice_detail VALUES(2,3214,112,‘wrong’);
INSERT INTO question_practice_detail VALUES(3,3214,113,‘wrong’);
INSERT INTO question_practice_detail VALUES(4,6543,111,‘right’);
INSERT INTO question_practice_detail VALUES(5,2315,115,‘right’);
INSERT INTO question_practice_detail VALUES(6,2315,116,‘right’);
INSERT INTO question_practice_detail VALUES(7,2315,117,‘wrong’);
INSERT INTO question_practice_detail VALUES(8,5432,117,‘wrong’);
INSERT INTO question_practice_detail VALUES(9,5432,112,‘wrong’);
INSERT INTO question_practice_detail VALUES(10,2131,113,‘right’);
INSERT INTO question_practice_detail VALUES(11,5432,113,‘wrong’);
INSERT INTO question_practice_detail VALUES(12,2315,115,‘right’);
INSERT INTO question_practice_detail VALUES(13,2315,116,‘right’);
INSERT INTO question_practice_detail VALUES(14,2315,117,‘wrong’);
INSERT INTO question_practice_detail VALUES(15,5432,117,‘wrong’);
INSERT INTO question_practice_detail VALUES(16,5432,112,‘wrong’);
INSERT INTO question_practice_detail VALUES(17,2131,113,‘right’);
INSERT INTO question_practice_detail VALUES(18,5432,113,‘wrong’);
INSERT INTO question_practice_detail VALUES(19,2315,117,‘wrong’);
INSERT INTO question_practice_detail VALUES(20,5432,117,‘wrong’);
INSERT INTO question_practice_detail VALUES(21,5432,112,‘wrong’);
INSERT INTO question_practice_detail VALUES(22,2131,113,‘right’);
INSERT INTO question_practice_detail VALUES(23,5432,113,‘wrong’);
INSERT INTO question_detail VALUES(1,111,‘hard’);
INSERT INTO question_detail VALUES(2,112,‘medium’);
INSERT INTO question_detail VALUES(3,113,‘easy’);
INSERT INTO question_detail VALUES(4,115,‘easy’);
INSERT INTO question_detail VALUES(5,116,‘medium’);
INSERT INTO question_detail VALUES(6,117,‘easy’);

输出：
5432|male|25|3.8
2131|male|28|3.3
2138|male|21|3.4
3214|male|None|4.0
5432|male|25|3.8
2131|male|28|3.3
4321|male|28|3.6

• SQL语句

select device_id,gender,age,gpa from user_profile where university=‘山东大学’ and gender = ‘male’
union all
select device_id,gender,age,gpa from user_profile where gender = ‘male’

select device_id,gender,age,gpa from user_profile where university='山东大学'and gender ='male'unionallselect device_id,gender,age,gpa from user_profile where gender ='male'

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