Hive 經典練習 50 題（完美解答版）
- 原始數據
- 數據清洗
- 練習 50 題
- 1、查詢"01"課程比"02"課程成績高的學生的信息及課程分數
- 2、查詢"01"課程比"02"課程成績低的學生的信息及課程分數
- 3、查詢平均成績大於等於60分的同學的學生編號和學生姓名和平均成績
- 4、查詢平均成績小於60分的同學的學生編號和學生姓名和平均成績(包括有成績的和無成績的)
- 5、查詢所有同學的學生編號、學生姓名、選課總數、所有課程的總成績
- 6、查詢"李"姓老師的數量
- 7、詢學過"張三"老師授課的同學的信息
- 8、查詢沒學過"張三"老師授課的同學的信息
- 9、查詢學過編號爲"01"並且也學過編號爲"02"的課程的同學的信息
- 10、查詢學過編號爲"01"但是沒有學過編號爲"02"的課程的同學的信息
- 11、查詢沒有學全所有課程的同學的信息
- 12、查詢至少有一門課與學號爲"01"的同學所學相同的同學的信息
- 13、查詢和"01"號的同學學習的課程完全相同的其他同學的信息
- 14、查詢沒學過"張三"老師講授的任一門課程的學生姓名
- 15、查詢兩門及其以上不及格課程的同學的學號，姓名及其平均成績
- 16、檢索"01"課程分數小於60，按分數降序排列的學生信息
- 17、按平均成績從高到低顯示所有學生的所有課程的成績以及平均成績
- 18、查詢各科成績最高分、最低分和平均分，以如下形式顯示：
- 19、按各科成績進行排序，並顯示排名
- 20、查詢學生的總成績並進行排名
- 21、查詢不同老師所教不同課程平均分從高到低顯示
- 22、查詢所有課程的成績第2名到第3名的學生信息及該課程成績
- 23、統計各科成績各分數段人數：課程編號,課程名稱,[100-85],[85-70],[70-60],[0-60]及所佔百分比
- 24、查詢學生平均成績及其名次
- 25、查詢各科成績前三名的記錄
- 26、查詢每門課程被選修的學生數
- 27、查詢出只有兩門課程的全部學生的學號和姓名
- 28、查詢男生、女生人數
- 29、查詢名字中含有"風"字的學生信息
- 30、查詢同名同性學生名單，並統計同名人數
- 31、查詢1990年出生的學生名單
- 32、查詢每門課程的平均成績，結果按平均成績降序排列，平均成績相同時，按課程編號升序排列
- 33、查詢平均成績大於等於85的所有學生的學號、姓名和平均成績
- 34、查詢課程名稱爲"數學"，且分數低於60的學生姓名和分數
- 35、查詢所有學生的課程及分數情況
- 36、查詢任何一門課程成績在70分以上的學生姓名、課程名稱和分數
- 37、查詢課程不及格的學生
- 38、查詢課程編號爲01且課程成績在80分以上的學生的學號和姓名
- 39、求每門課程的學生人數
- 40、查詢選修"張三"老師所授課程的學生中，成績最高的學生信息及其成績
- 41、查詢不同課程成績相同的學生的學生編號、課程編號、學生成績
- 42、查詢每門課程成績最好的前三名
- 43、統計每門課程的學生選修人數（超過5人的課程才統計）
- 44、檢索至少選修兩門課程的學生學號
- 45、查詢選修了全部課程的學生信息
- 46、查詢各學生的年齡(週歲)
- 47、查詢本週過生日的學生
- 48、查詢下週過生日的學生
- 49、查詢本月過生日的學生
- 50、查詢12月份過生日的學生
原始數據
data 文件中有 student、course、teacher、score 四張表，表中數據如下：
student.csv
s_id,s_name,s_birth,s_sex
1,趙雷,1990-01-01,男
2,錢電,1990-12-21,男
3,孫風,1990-05-20,男
4,李雲,1990-08-06,男
5,周梅,1991-12-01,
6,吳蘭,1992-03-01,女
7,鄭竹,1989-07-01,女
8,王菊,1990-01-20,女
course.csv
c_id,c_name,t_id
1,語文,2
2,數學,1
3,英語,4
teacher.csv
t_id,t_name
1,張三
2,李四
3,王五
score.csv
s_id,c_id,s_score
1,1,80
1,2,90
1,3,99
2,1,70
2,2,60
2,3,180
3,1,80
3,2,80
3,3,80
4,1,50
4,2,30
4,3,-20
5,1,76
5,2,87
6,1,31
6,3,34
7,2,89
7,3,98
數據清洗
要求：
-
將 data 文件中的數據分別導入到 HIVE 中構建 ODS 層的四張外部表
ext_student\ext_course\ext_teacher\ext_score -
對數據進行清洗生成對應 DWD 層的四張內部表
(1) student 性別缺失，請將未填充性別的人員設置爲女
(2) course 教員編號錯誤，請將沒有擔任課程的教員編號填充到錯誤的教員編號
(3) score 請根據課程製作分區表，並在填充數據時檢驗分數是否合理，對不合理的分數計算該學員其他課程的平均成績作爲不合理成績的分數
1、上傳數據
在 hdfs 上創建數據文件目錄
hdfs dfs -mkdir -p /tmp/hive_test/data/student
hdfs dfs -mkdir -p /tmp/hive_test/data/course
hdfs dfs -mkdir -p /tmp/hive_test/data/teacher
hdfs dfs -mkdir -p /tmp/hive_test/data/score
上傳 csv 文件到 hdfs 數據文件目錄
hdfs dfs -put /opt/data/student.csv /tmp/hive_test/data/student
hdfs dfs -put /opt/data/course.csv /tmp/hive_test/data/course
hdfs dfs -put /opt/data/teacher.csv /tmp/hive_test/data/teacher
hdfs dfs -put /opt/data/score.csv /tmp/hive_test/data/score
2、導入數據
創建數據庫 hive_test
drop database if exists hive_test cascade;
create database hive_test;
use hive_test;
創建外部表 ext_student
create external table if not exists ext_student (
s_id int,
s_name string,
s_birth date,
s_sex string
)
row format delimited fields terminated by ','
stored as textfile
location '/tmp/hive_test/data/student'
tblproperties("skip.header.line.count"="1")
創建外部表 ext_course
create external table if not exists ext_course (
c_id int,
c_name string,
t_id int
)
row format delimited fields terminated by ','
stored as textfile
location '/tmp/hive_test/data/course'
tblproperties("skip.header.line.count"="1")
創建外部表 ext_teacher
create external table if not exists ext_teacher (
t_id int,
t_name string
)
row format delimited fields terminated by ','
stored as textfile
location '/tmp/hive_test/data/teacher'
tblproperties("skip.header.line.count"="1")
創建外部表 ext_score
create external table if not exists ext_score (
s_id int,
c_id int,
s_score int
)
row format delimited fields terminated by ','
stored as textfile
location '/tmp/hive_test/data/score'
tblproperties("skip.header.line.count"="1")
3、清洗數據
創建內部表 student，將未填充性別的人員設置爲女
create table if not exists student as
select s_id,s_name,s_birth,if(s_sex = '', '女', s_sex) as s_sex from ext_student;
創建內部表 teacher，數據正常無需清洗，直接導入原始數據
create table if not exists teacher as
select * from ext_teacher;
創建內部表 course，將沒有擔任課程的教員編號填充到錯誤的教員編號
create table if not exists course as
with
-- t1：正確的課程信息及教員編號：c_id,c_name,t_id
t1 as (select c_id,c_name,t_id from ext_course c where exists(select * from teacher t where t.t_id = c.t_id)),
-- t2：教員編號錯誤的課程信息：c_id,c_name
t2 as (select c.c_id,c.c_name from ext_course c where not exists(select * from t1 where t1.t_id = c.t_id)),
-- t3：未擔任課程的教員編號：t_id
t3 as (select t.t_id from teacher t where not exists(select * from ext_course c where c.t_id = t.t_id)),
-- t4：t2和t3拼接（交叉連接），將未擔任課程的教員編號拼到教員編號錯誤的課程信息後，再與t1合併，即爲正確的數據
t4 as (select c_id,c_name,t_id from t1 union all select c_id,c_name,t_id from t2,t3)
-- union後順序會亂，需要按照課程id排下序
select * from t4 order by c_id
創建內部表 score，按照課程分區
create table if not exists score (
s_id int,
s_score int
)
partitioned by (c_id int)
row format delimited fields terminated by ','
stored as textfile
-- 開啓動態分區
set hive.exec.dynamic.partition=true
set hive.exec.dynamic.partition.mode=nonstrict
-- 清洗外部表ext_score並將數據導入內部表score
-- 對不合理成績的分數計算該學員其他課程的平均成績替換該分數
with
t1 as (select s_id,round(avg(s_score), 1) as avg_score from ext_score where s_score between 0 and 100 group by s_id)
insert overwrite table score partition(c_id)
select sc.s_id,if(sc.s_score < 0 or sc.s_score > 100, t1.avg_score, sc.s_score) as s_score,sc.c_idfrom ext_score sc inner join t1 on sc.s_id = t1.s_id
4、驗證數據
查看學生表 student
select * from student;
+------+--------+------------+-------+
| s_id | s_name | s_birth | s_sex |
+------+--------+------------+-------+
| 1 | 趙雷 | 1990-01-01 | 男 |
| 2 | 錢電 | 1990-12-21 | 男 |
| 3 | 孫風 | 1990-05-20 | 男 |
| 4 | 李雲 | 1990-08-06 | 男 |
| 5 | 周梅 | 1991-12-01 | 女 |
| 6 | 吳蘭 | 1992-03-01 | 女 |
| 7 | 鄭竹 | 1989-07-01 | 女 |
| 8 | 王菊 | 1990-01-20 | 女 |
+------+--------+------------+-------+
查看課程表 course
select * from course;
+------+--------+------+
| c_id | c_name | t_id |
+------+--------+------+
| 1 | 語文 | 2 |
| 2 | 數學 | 1 |
| 3 | 英語 | 3 |
+------+--------+------+
查看教師表 teacher
select * from teacher;
+------+--------+
| t_id | t_name |
+------+--------+
| 1 | 張三 |
| 2 | 李四 |
| 3 | 王五 |
+------+--------+
查看成績表 score
select * from score;
+------+------+---------+
| s_id | c_id | s_score |
+------+------+---------+
| 1 | 1 | 80 |
| 1 | 2 | 90 |
| 1 | 3 | 99 |
| 2 | 1 | 70 |
| 2 | 2 | 60 |
| 2 | 3 | 65 |
| 3 | 1 | 80 |
| 3 | 2 | 80 |
| 3 | 3 | 80 |
| 4 | 1 | 50 |
| 4 | 2 | 30 |
| 4 | 3 | 40 |
| 5 | 1 | 76 |
| 5 | 2 | 87 |
| 6 | 1 | 31 |
| 6 | 3 | 34 |
| 7 | 2 | 89 |
| 7 | 3 | 98 |
+------+------+---------+
表關係如下
練習 50 題
1、查詢"01"課程比"02"課程成績高的學生的信息及課程分數
with
sc1 as (select * from score where c_id = 1),
sc2 as (select * from score where c_id = 2)
select s.*,sc1.s_score as score_01,sc2.s_score as score_02
from student s
inner join sc1 on s.s_id = sc1.s_id
inner join sc2 on s.s_id = sc2.s_id
where sc1.s_score > sc2.s_score;
+------+--------+------------+-------+----------+----------+
| s_id | s_name | s_birth | s_sex | score_01 | score_02 |
+------+--------+------------+-------+----------+----------+
| 2 | 錢電 | 1990-12-21 | 男 | 70 | 60 |
| 4 | 李雲 | 1990-08-06 | 男 | 50 | 30 |
+------+--------+------------+-------+----------+----------+
2、查詢"01"課程比"02"課程成績低的學生的信息及課程分數
with
sc1 as (select * from score where c_id = 1),
sc2 as (select * from score where c_id = 2)
select s.*,sc1.s_score as score_01,sc2.s_score as score_02
from student s
inner join sc1 on s.s_id = sc1.s_id
inner join sc2 on s.s_id = sc2.s_id
where sc1.s_score < sc2.s_score;
+------+--------+------------+-------+----------+----------+
| s_id | s_name | s_birth | s_sex | score_01 | score_02 |
+------+--------+------------+-------+----------+----------+
| 1 | 趙雷 | 1990-01-01 | 男 | 80 | 90 |
| 5 | 周梅 | 1991-12-01 | 女 | 76 | 87 |
+------+--------+------------+-------+----------+----------+
3、查詢平均成績大於等於60分的同學的學生編號和學生姓名和平均成績
with
t1 as (select s_id,avg(s_score) as avg_score from score group by s_id having avg_score >= 60)
select s.s_id,s.s_name,round(avg_score, 2) as avg_score
from student s
inner join t1 on s.s_id = t1.s_id;
+------+--------+-----------+
| s_id | s_name | avg_score |
+------+--------+-----------+
| 1 | 趙雷 | 89.67 |
| 2 | 錢電 | 65.00 |
| 3 | 孫風 | 80.00 |
| 5 | 周梅 | 81.50 |
| 7 | 鄭竹 | 93.50 |
+------+--------+-----------+
4、查詢平均成績小於60分的同學的學生編號和學生姓名和平均成績(包括有成績的和無成績的)
with
t1 as (select s_id,avg(s_score) as avg_score from score group by s_id)
select s.s_id,s.s_name,if(avg_score is null, 0, round(avg_score, 2)) as avg_score
from student s
left join t1 on s.s_id = t1.s_id
where avg_score is null or avg_score < 60;
+------+--------+-----------+
| s_id | s_name | avg_score |
+------+--------+-----------+
| 4 | 李雲 | 40.00 |
| 6 | 吳蘭 | 32.50 |
| 8 | 王菊 | 0.00 |
+------+--------+-----------+
5、查詢所有同學的學生編號、學生姓名、選課總數、所有課程的總成績
with
t1 as (select s_id,count(*) as cnt_course,sum(s_score) as sum_score from score group by s_id)
select s.s_id,s.s_name,if(cnt_course is null, 0, cnt_course) as cnt_course,if(sum_score is null, 0, sum_score) as sum_score
from student s
left join t1 on s.s_id = t1.s_id;
+------+--------+------------+-----------+
| s_id | s_name | cnt_course | sum_score |
+------+--------+------------+-----------+
| 1 | 趙雷 | 3 | 269 |
| 2 | 錢電 | 3 | 195 |
| 3 | 孫風 | 3 | 240 |
| 4 | 李雲 | 3 | 120 |
| 5 | 周梅 | 2 | 163 |
| 6 | 吳蘭 | 2 | 65 |
| 7 | 鄭竹 | 2 | 187 |
| 8 | 王菊 | 0 | 0 |
+------+--------+------------+-----------+
6、查詢"李"姓老師的數量
select count(*) as cnt_name_li
from teacher
where t_name like '李%';
+-------------+
| cnt_name_li |
+-------------+
| 1 |
+-------------+
7、詢學過"張三"老師授課的同學的信息
with
t1 as (select c_id from course c inner join teacher t on c.t_id = t.t_id where t_name = '張三'),
t2 as (select distinct s_id from score sc inner join t1 on sc.c_id = t1.c_id)
select *
from student s
where exists(select * from t2 where s.s_id = t2.s_id);
+------+--------+------------+-------+
| s_id | s_name | s_birth | s_sex |
+------+--------+------------+-------+
| 1 | 趙雷 | 1990-01-01 | 男 |
| 2 | 錢電 | 1990-12-21 | 男 |
| 3 | 孫風 | 1990-05-20 | 男 |
| 4 | 李雲 | 1990-08-06 | 男 |
| 5 | 周梅 | 1991-12-01 | 女 |
| 7 | 鄭竹 | 1989-07-01 | 女 |
+------+--------+------------+-------+
8、查詢沒學過"張三"老師授課的同學的信息
with
t1 as (select c_id from course c inner join teacher t on c.t_id = t.t_id where t_name = '張三'),
t2 as (select distinct s_id from score sc inner join t1 on sc.c_id = t1.c_id)
select *
from student s
where not exists(select * from t2 where s.s_id = t2.s_id);
+------+--------+------------+-------+
| s_id | s_name | s_birth | s_sex |
+------+--------+------------+-------+
| 6 | 吳蘭 | 1992-03-01 | 女 |
| 8 | 王菊 | 1990-01-20 | 女 |
+------+--------+------------+-------+
9、查詢學過編號爲"01"並且也學過編號爲"02"的課程的同學的信息
with
t1 as (select s_id from score where c_id in ('01','02') group by s_id having count(*) = 2)
select *
from student s
where exists(select * from t1 where s.s_id = t1.s_id);
+------+--------+------------+-------+
| s_id | s_name | s_birth | s_sex |
+------+--------+------------+-------+
| 1 | 趙雷 | 1990-01-01 | 男 |
| 2 | 錢電 | 1990-12-21 | 男 |
| 3 | 孫風 | 1990-05-20 | 男 |
| 4 | 李雲 | 1990-08-06 | 男 |
| 5 | 周梅 | 1991-12-01 | 女 |
+------+--------+------------+-------+
10、查詢學過編號爲"01"但是沒有學過編號爲"02"的課程的同學的信息
with
t1 as (select s_id from score where c_id = 1),
t2 as (select s_id from score where c_id = 2),
t3 as (select t1.s_id as s_id from t1 left join t2 on t1.s_id = t2.s_id where t2.s_id is null)
select *
from student s
where exists(select * from t3 where s.s_id = t3.s_id);
+------+--------+------------+-------+
| s_id | s_name | s_birth | s_sex |
+------+--------+------------+-------+
| 6 | 吳蘭 | 1992-03-01 | 女 |
+------+--------+------------+-------+
11、查詢沒有學全所有課程的同學的信息
with
t1 as (select count(*) as cnt_course from course),
t2 as (select s_id,count(*) as cnt_course from score group by s_id),
t3 as (select s_id from t1 cross join t2 where t1.cnt_course = t2.cnt_course)
select *
from student s
where not exists(select * from t3 where s.s_id = t3.s_id);
+------+--------+------------+-------+
| s_id | s_name | s_birth | s_sex |
+------+--------+------------+-------+
| 5 | 周梅 | 1991-12-01 | 女 |
| 6 | 吳蘭 | 1992-03-01 | 女 |
| 7 | 鄭竹 | 1989-07-01 | 女 |
| 8 | 王菊 | 1990-01-20 | 女 |
+------+--------+------------+-------+
12、查詢至少有一門課與學號爲"01"的同學所學相同的同學的信息
with
t1 as (select c_id from score where s_id = 1),
t2 as (select distinct s_id from score sc inner join t1 on sc.c_id = t1.c_id)
select *
from student s
where exists(select * from t2 where s.s_id = t2.s_id);
+------+--------+------------+-------+
| s_id | s_name | s_birth | s_sex |
+------+--------+------------+-------+
| 1 | 趙雷 | 1990-01-01 | 男 |
| 2 | 錢電 | 1990-12-21 | 男 |
| 3 | 孫風 | 1990-05-20 | 男 |
| 4 | 李雲 | 1990-08-06 | 男 |
| 5 | 周梅 | 1991-12-01 | 女 |
| 6 | 吳蘭 | 1992-03-01 | 女 |
| 7 | 鄭竹 | 1989-07-01 | 女 |
+------+--------+------------+-------+
13、查詢和"01"號的同學學習的課程完全相同的其他同學的信息
with
t1 as (select c_id from score where s_id = 1),
t2 as (select count(*) as cnt_course from t1),
t3 as (select s_id,count(*) as cnt_course from score sc inner join t1 on sc.c_id = t1.c_id where s_id != 1 group by s_id),
t4 as (select s_id from t2 cross join t3 where t2.cnt_course = t3.cnt_course)
select *
from student s
where exists(select * from t4 where s.s_id = t4.s_id);
+------+--------+------------+-------+
| s_id | s_name | s_birth | s_sex |
+------+--------+------------+-------+
| 2 | 錢電 | 1990-12-21 | 男 |
| 3 | 孫風 | 1990-05-20 | 男 |
| 4 | 李雲 | 1990-08-06 | 男 |
+------+--------+------------+-------+
14、查詢沒學過"張三"老師講授的任一門課程的學生姓名
with
t1 as (select c_id from course c inner join teacher t on c.t_id = t.t_id where t_name = '張三'),
t2 as (select s_id from score sc inner join t1 on sc.c_id = t1.c_id)
select s_name
from student s
where not exists(select * from t2 where s.s_id = t2.s_id);
+--------+
| s_name |
+--------+
| 吳蘭 |
| 王菊 |
+--------+
15、查詢兩門及其以上不及格課程的同學的學號，姓名及其平均成績
with
t1 as (select s_id from score where s_score < 60 group by s_id having count(*) >= 2)
select s.s_id,s.s_name,round(avg(s_score), 2) as avg_score
from student s
inner join t1 on s.s_id = t1.s_id
inner join score sc on s.s_id = sc.s_id
group by s.s_id,s.s_name;
+------+--------+-----------+
| s_id | s_name | avg_score |
+------+--------+-----------+
| 4 | 李雲 | 40.00 |
| 6 | 吳蘭 | 32.50 |
+------+--------+-----------+
16、檢索"01"課程分數小於60，按分數降序排列的學生信息
with
t1 as (select s_id,s_score from score where c_id = 1 and s_score < 60)
select s.*,s_score as score_01
from student s
inner join t1 on s.s_id = t1.s_id
order by score_01 desc;
+------+--------+------------+-------+----------+
| s_id | s_name | s_birth | s_sex | score_01 |
+------+--------+------------+-------+----------+
| 4 | 李雲 | 1990-08-06 | 男 | 50 |
| 6 | 吳蘭 | 1992-03-01 | 女 | 31 |
+------+--------+------------+-------+----------+
17、按平均成績從高到低顯示所有學生的所有課程的成績以及平均成績
t1 as (
select
s.s_id,s.s_name,
sum(case c_id when 1 then s_score else 0 end) as chinese,
sum(case c_id when 2 then s_score else 0 end) as math,
sum(case c_id when 3 then s_score else 0 end) as english,
round(avg(s_score), 2) as avg_score
from student s
left join score sc
on s.s_id = sc.s_id
group by s.s_id,s.s_name
order by avg_score desc
)
select s_id,s_name,chinese,math,english,if(avg_score is null, 0, avg_score) as avg_score
from t1;
+------+--------+---------+------+---------+-----------+
| s_id | s_name | chinese | math | english | avg_score |
+------+--------+---------+------+---------+-----------+
| 7 | 鄭竹 | 0 | 89 | 98 | 93.50 |
| 1 | 趙雷 | 80 | 90 | 99 | 89.67 |
| 5 | 周梅 | 76 | 87 | 0 | 81.50 |
| 3 | 孫風 | 80 | 80 | 80 | 80.00 |
| 2 | 錢電 | 70 | 60 | 65 | 65.00 |
| 4 | 李雲 | 50 | 30 | 40 | 40.00 |
| 6 | 吳蘭 | 31 | 0 | 34 | 32.50 |
| 8 | 王菊 | 0 | 0 | 0 | 0.00 |
+------+--------+---------+------+---------+-----------+
18、查詢各科成績最高分、最低分和平均分，以如下形式顯示：
課程ID，課程name，最高分，最低分，平均分，及格率，中等率，優良率，優秀率
– 及格爲>=60，中等爲：70-80，優良爲：80-90，優秀爲：>=90
select
c.c_id as course_id,c.c_name as course_name,
max(s_score) as max_score,
min(s_score) as ming_score,
round(avg(s_score), 2) as avg_score,
concat(round(sum(case when s_score >= 60 then 1 else 0 end) / count(*) * 100, 2), '%') as pass_rate,
concat(round(sum(case when s_score between 70 and 80 then 1 else 0 end) / count(*) * 100, 2), '%') as medium_rate,
concat(round(sum(case when s_score between 80 and 90 then 1 else 0 end) / count(*) * 100, 2), '%') as good_rate,
concat(round(sum(case when s_score >= 90 then 1 else 0 end) / count(*) * 100, 2), '%') as excellent_rate
from course c
inner join score s on c.c_id = s.c_id
group by c.c_id,c.c_name;
+-----------+-------------+-----------+------------+-----------+-----------+-------------+-----------+----------------+
| course_id | course_name | max_score | ming_score | avg_score | pass_rate | medium_rate | good_rate | excellent_rate |
+-----------+-------------+-----------+------------+-----------+-----------+-------------+-----------+----------------+
| 1 | 語文 | 80 | 31 | 64.50 | 66.67% | 66.67% | 33.33% | 0.00% |
| 2 | 數學 | 90 | 30 | 72.67 | 83.33% | 16.67% | 66.67% | 16.67% |
| 3 | 英語 | 99 | 34 | 69.33 | 66.67% | 16.67% | 16.67% | 33.33% |
+-----------+-------------+-----------+------------+-----------+-----------+-------------+-----------+----------------+
19、按各科成績進行排序，並顯示排名
select
c.c_id,c.c_name,s.s_id,s.s_name,s_score,row_number() over(partition by c.c_id order by s_score desc) as rank
from score sc
inner join student s on sc.s_id = s.s_id
inner join course c on sc.c_id = c.c_id;
+------+--------+------+--------+---------+------+
| c_id | c_name | s_id | s_name | s_score | rank |
+------+--------+------+--------+---------+------+
| 1 | 語文 | 1 | 趙雷 | 80 | 1 |
| 1 | 語文 | 3 | 孫風 | 80 | 2 |
| 1 | 語文 | 5 | 周梅 | 76 | 3 |
| 1 | 語文 | 2 | 錢電 | 70 | 4 |
| 1 | 語文 | 4 | 李雲 | 50 | 5 |
| 1 | 語文 | 6 | 吳蘭 | 31 | 6 |
| 2 | 數學 | 1 | 趙雷 | 90 | 1 |
| 2 | 數學 | 7 | 鄭竹 | 89 | 2 |
| 2 | 數學 | 5 | 周梅 | 87 | 3 |
| 2 | 數學 | 3 | 孫風 | 80 | 4 |
| 2 | 數學 | 2 | 錢電 | 60 | 5 |
| 2 | 數學 | 4 | 李雲 | 30 | 6 |
| 3 | 英語 | 1 | 趙雷 | 99 | 1 |
| 3 | 英語 | 7 | 鄭竹 | 98 | 2 |
| 3 | 英語 | 3 | 孫風 | 80 | 3 |
| 3 | 英語 | 2 | 錢電 | 65 | 4 |
| 3 | 英語 | 4 | 李雲 | 40 | 5 |
| 3 | 英語 | 6 | 吳蘭 | 34 | 6 |
+------+--------+------+--------+---------+------+
20、查詢學生的總成績並進行排名
with
t1 as (select s_id,sum(s_score) as sum_score from score group by s_id)
select s.s_id,s.s_name,sum_score,row_number() over(order by sum_score desc) as rank
from student s
inner join t1 on s.s_id = t1.s_id;
+------+--------+-----------+------+
| s_id | s_name | sum_score | rank |
+------+--------+-----------+------+
| 1 | 趙雷 | 269 | 1 |
| 3 | 孫風 | 240 | 2 |
| 2 | 錢電 | 195 | 3 |
| 7 | 鄭竹 | 187 | 4 |
| 5 | 周梅 | 163 | 5 |
| 4 | 李雲 | 120 | 6 |
| 6 | 吳蘭 | 65 | 7 |
+------+--------+-----------+------+
21、查詢不同老師所教不同課程平均分從高到低顯示
select t.t_id,t.t_name,c.c_id,c.c_name,round(avg(s_score), 2) as avg_score
from score sc
inner join course c on sc.c_id = c.c_id
inner join teacher t on t.t_id = c.t_id
group by t.t_id,t.t_name,c.c_id,c.c_name
order by t.t_id,avg_score desc;
+------+--------+------+--------+-----------+
| t_id | t_name | c_id | c_name | avg_score |
+------+--------+------+--------+-----------+
| 1 | 張三 | 2 | 數學 | 72.67 |
| 2 | 李四 | 1 | 語文 | 64.50 |
| 3 | 王五 | 3 | 英語 | 69.33 |
+------+--------+------+--------+-----------+
22、查詢所有課程的成績第2名到第3名的學生信息及該課程成績
with
t1 as (
select
c.c_id,c.c_name,s.*,s_score,row_number() over(partition by c.c_id order by s_score desc) as rank
from score sc
inner join student s on sc.s_id = s.s_id
inner join course c on sc.c_id = c.c_id
)
select * from t1 where rank in (2,3);
+------+--------+------+--------+------------+-------+---------+------+
| c_id | c_name | s_id | s_name | s_birth | s_sex | s_score | rank |
+------+--------+------+--------+------------+-------+---------+------+
| 1 | 語文 | 3 | 孫風 | 1990-05-20 | 男 | 80 | 2 |
| 1 | 語文 | 5 | 周梅 | 1991-12-01 | 女 | 76 | 3 |
| 2 | 數學 | 7 | 鄭竹 | 1989-07-01 | 女 | 89 | 2 |
| 2 | 數學 | 5 | 周梅 | 1991-12-01 | 女 | 87 | 3 |
| 3 | 英語 | 7 | 鄭竹 | 1989-07-01 | 女 | 98 | 2 |
| 3 | 英語 | 3 | 孫風 | 1990-05-20 | 男 | 80 | 3 |
+------+--------+------+--------+------------+-------+---------+------+
23、統計各科成績各分數段人數：課程編號,課程名稱,[100-85],[85-70],[70-60],[0-60]及所佔百分比
select
c.c_id as course_id,c.c_name as course_name,
sum(case when s_score between 85 and 100 then 1 else 0 end) as number_100_85,
concat(round(sum(case when s_score between 85 and 100 then 1 else 0 end) / count(*) * 100, 2), '%') as percentage,
sum(case when s_score between 70 and 85 then 1 else 0 end) as number_85_70,
concat(round(sum(case when s_score between 70 and 85 then 1 else 0 end) / count(*) * 100, 2), '%') as percentage,
sum(case when s_score between 60 and 70 then 1 else 0 end) as number_70_60,
concat(round(sum(case when s_score between 60 and 70 then 1 else 0 end) / count(*) * 100, 2), '%') as percentage,
sum(case when s_score between 0 and 60 then 1 else 0 end) as number_0_60,
concat(round(sum(case when s_score between 0 and 60 then 1 else 0 end) / count(*) * 100, 2), '%') as percentage
from course c
inner join score sc
on c.c_id = sc.c_id
group by c.c_id,c.c_name;
+-----------+-------------+---------------+------------+--------------+------------+--------------+------------+-------------+------------+
| course_id | course_name | number_100_85 | percentage | number_85_70 | percentage | number_70_60 | percentage | number_0_60 | percentage |
+-----------+-------------+---------------+------------+--------------+------------+--------------+------------+-------------+------------+
| 1 | 語文 | 0 | 0.00% | 4 | 66.67% | 1 | 16.67% | 2 | 33.33% |
| 2 | 數學 | 3 | 50.00% | 1 | 16.67% | 1 | 16.67% | 2 | 33.33% |
| 3 | 英語 | 2 | 33.33% | 1 | 16.67% | 1 | 16.67% | 2 | 33.33% |
+-----------+-------------+---------------+------------+--------------+------------+--------------+------------+-------------+------------+
24、查詢學生平均成績及其名次
with
t1 as (select s_id,round(avg(s_score), 2) as avg_score from score group by s_id)
select s.s_id,s.s_name,avg_score,row_number() over(order by avg_score desc) as rank
from student s
inner join t1 on s.s_id = t1.s_id;
+------+--------+-----------+------+
| s_id | s_name | avg_score | rank |
+------+--------+-----------+------+
| 7 | 鄭竹 | 93.50 | 1 |
| 1 | 趙雷 | 89.67 | 2 |
| 5 | 周梅 | 81.50 | 3 |
| 3 | 孫風 | 80.00 | 4 |
| 2 | 錢電 | 65.00 | 5 |
| 4 | 李雲 | 40.00 | 6 |
| 6 | 吳蘭 | 32.50 | 7 |
+------+--------+-----------+------+
25、查詢各科成績前三名的記錄
with
t1 as (
select
c.c_id,c.c_name,s.s_id,s.s_name,s_score,row_number() over(partition by c.c_id order by s_score desc) as rank
from score sc
inner join student s on sc.s_id = s.s_id
inner join course c on sc.c_id = c.c_id
)
select * from t1 where rank <= 3;
+------+--------+------+--------+---------+------+
| c_id | c_name | s_id | s_name | s_score | rank |
+------+--------+------+--------+---------+------+
| 1 | 語文 | 1 | 趙雷 | 80 | 1 |
| 1 | 語文 | 3 | 孫風 | 80 | 2 |
| 1 | 語文 | 5 | 周梅 | 76 | 3 |
| 2 | 數學 | 1 | 趙雷 | 90 | 1 |
| 2 | 數學 | 7 | 鄭竹 | 89 | 2 |
| 2 | 數學 | 5 | 周梅 | 87 | 3 |
| 3 | 英語 | 1 | 趙雷 | 99 | 1 |
| 3 | 英語 | 7 | 鄭竹 | 98 | 2 |
| 3 | 英語 | 3 | 孫風 | 80 | 3 |
+------+--------+------+--------+---------+------+
26、查詢每門課程被選修的學生數
with
t1 as (select c_id,count(*) as cnt_student from score group by c_id)
select c.c_id,c.c_name,cnt_student
from course c
inner join t1 on c.c_id = t1.c_id;
+------+--------+-------------+
| c_id | c_name | cnt_student |
+------+--------+-------------+
| 1 | 語文 | 6 |
| 2 | 數學 | 6 |
| 3 | 英語 | 6 |
+------+--------+-------------+
27、查詢出只有兩門課程的全部學生的學號和姓名
with
t1 as (select s_id from score group by s_id having count(*) = 2)
select *
from student s
where exists(select * from t1 where s.s_id = t1.s_id);
+------+--------+
| s_id | s_name |
+------+--------+
| 5 | 周梅 |
| 6 | 吳蘭 |
| 7 | 鄭竹 |
+------+--------+
28、查詢男生、女生人數
select s_sex,count(*) as cnt_sex
from student
group by s_sex;
+-------+---------+
| s_sex | cnt_sex |
+-------+---------+
| 女 | 4 |
| 男 | 4 |
+-------+---------+
29、查詢名字中含有"風"字的學生信息
select *
from student
where s_name like '%風%';
+------+--------+------------+-------+
| s_id | s_name | s_birth | s_sex |
+------+--------+------------+-------+
| 3 | 孫風 | 1990-05-20 | 男 |
+------+--------+------------+-------+
30、查詢同名同性學生名單，並統計同名人數
with
t1 as (
select s_name,s_sex,count(*) as cnt_student
from student
group by s_name,s_sex
having cnt_student > 1
)
select * from student s
inner join t1 on s.s_name = t1.s_name and s.s_sex = t1.s_sex;
+-----------+
| Empty set |
+-----------+
31、查詢1990年出生的學生名單
select *
from student
where year(s_birth) = '1990';
+------+--------+------------+-------+
| s_id | s_name | s_birth | s_sex |
+------+--------+------------+-------+
| 1 | 趙雷 | 1990-01-01 | 男 |
| 2 | 錢電 | 1990-12-21 | 男 |
| 3 | 孫風 | 1990-05-20 | 男 |
| 4 | 李雲 | 1990-08-06 | 男 |
| 8 | 王菊 | 1990-01-20 | 女 |
+------+--------+------------+-------+
32、查詢每門課程的平均成績，結果按平均成績降序排列，平均成績相同時，按課程編號升序排列
with
t1 as (select c_id,round(avg(s_score), 2) as avg_score from score group by c_id)
select c.c_id,c.c_name,avg_score
from course c
inner join t1 on c.c_id = t1.c_id
order by avg_score desc,c.c_id;
+------+--------+-----------+
| c_id | c_name | avg_score |
+------+--------+-----------+
| 2 | 數學 | 72.67 |
| 3 | 英語 | 69.33 |
| 1 | 語文 | 64.50 |
+------+--------+-----------+
33、查詢平均成績大於等於85的所有學生的學號、姓名和平均成績
with
t1 as (select s_id,avg(s_score) as avg_score from score group by s_id having avg_score >= 85)
select s.s_id,s.s_name,round(avg_score, 2)
from student s
inner join t1 on s.s_id = t1.s_id;
+------+--------+-----------+
| s_id | s_name | avg_score |
+------+--------+-----------+
| 1 | 趙雷 | 89.67 |
| 7 | 鄭竹 | 93.50 |
+------+--------+-----------+
34、查詢課程名稱爲"數學"，且分數低於60的學生姓名和分數
with
t1 as (
select s_id,s_score
from score sc
inner join course c on sc.c_id = c.c_id
where c_name = '數學'
and s_score < 60
)
select s_name,s_score
from student s
inner join t1 on s.s_id = t1.s_id;
+--------+---------+
| s_name | s_score |
+--------+---------+
| 李雲 | 30 |
+--------+---------+
35、查詢所有學生的課程及分數情況
select
s.s_id,s.s_name,
sum(case c_id when 1 then s_score else 0 end) as chinese,
sum(case c_id when 2 then s_score else 0 end) as math,
sum(case c_id when 3 then s_score else 0 end) as english
from student s
left join score sc
on s.s_id = sc.s_id
group by s.s_id,s.s_name;
+------+--------+---------+------+---------+
| s_id | s_name | chinese | math | english |
+------+--------+---------+------+---------+
| 1 | 趙雷 | 80 | 90 | 99 |
| 2 | 錢電 | 70 | 60 | 65 |
| 3 | 孫風 | 80 | 80 | 80 |
| 4 | 李雲 | 50 | 30 | 40 |
| 5 | 周梅 | 76 | 87 | 0 |
| 6 | 吳蘭 | 31 | 0 | 34 |
| 7 | 鄭竹 | 0 | 89 | 98 |
| 8 | 王菊 | 0 | 0 | 0 |
+------+--------+---------+------+---------+
36、查詢任何一門課程成績在70分以上的學生姓名、課程名稱和分數
with
t1 as (select s_id,c_id,s_score from score where s_score > 70 group by s_id,c_id,s_score)
select s_name,c_name,s_score
from t1
inner join student s on t1.s_id = s.s_id
inner join course c on t1.c_id = c.c_id;
+--------+--------+---------+
| s_name | c_name | s_score |
+--------+--------+---------+
| 趙雷 | 語文 | 80 |
| 孫風 | 語文 | 80 |
| 周梅 | 語文 | 76 |
| 鄭竹 | 數學 | 89 |
+--------+--------+---------+
37、查詢課程不及格的學生
select s.s_id,s.s_name,c.c_id,c.c_name,s_score
from score sc
inner join student s on sc.s_id = s.s_id
inner join course c on sc.c_id = c.c_id
where s_score < 60;
+------+--------+------+--------+---------+
| s_id | s_name | c_id | c_name | s_score |
+------+--------+------+--------+---------+
| 4 | 李雲 | 1 | 語文 | 50 |
| 4 | 李雲 | 2 | 數學 | 30 |
| 4 | 李雲 | 3 | 英語 | 40 |
| 6 | 吳蘭 | 1 | 語文 | 31 |
| 6 | 吳蘭 | 3 | 英語 | 34 |
+------+--------+------+--------+---------+
38、查詢課程編號爲01且課程成績在80分以上的學生的學號和姓名
with
t1 as (select s_id from score where c_id = 1 and s_score >= 80)
select s_id,s_name
from student s
where exists(select * from t1 where s.s_id = t1.s_id);
+------+--------+
| s_id | s_name |
+------+--------+
| 1 | 趙雷 |
| 3 | 孫風 |
+------+--------+
39、求每門課程的學生人數
with
t1 as (select c_id,count(*) as cnt_student from score group by c_id)
select c.c_id,c.c_name,cnt_student
from course c
inner join t1 on c.c_id = t1.c_id;
+------+--------+-------------+
| c_id | c_name | cnt_student |
+------+--------+-------------+
| 1 | 語文 | 6 |
| 2 | 數學 | 6 |
| 3 | 英語 | 6 |
+------+--------+-------------+
40、查詢選修"張三"老師所授課程的學生中，成績最高的學生信息及其成績
with
t1 as (select c_id from course c inner join teacher t on c.t_id = t.t_id where t_name = '張三'),
t2 as (select s_id,s_score from score sc inner join t1 on sc.c_id = t1.c_id order by s_score desc limit 1)
select s.*,s_score as max_score
from student s
inner join t2 on s.s_id = t2.s_id;
+------+--------+------------+-------+-----------+
| s_id | s_name | s_birth | s_sex | max_score |
+------+--------+------------+-------+-----------+
| 1 | 趙雷 | 1990-01-01 | 男 | 90 |
+------+--------+------------+-------+-----------+
41、查詢不同課程成績相同的學生的學生編號、課程編號、學生成績
with
t1 as (select *,count(*) over(partition by s_score) as cnt_student from score)
select s_id,c_id,s_score from t1 where cnt_student > 1;
+------+------+---------+
| s_id | c_id | s_score |
+------+------+---------+
| 1 | 1 | 80 |
| 3 | 1 | 80 |
| 3 | 2 | 80 |
| 3 | 3 | 80 |
+------+------+---------+
42、查詢每門課程成績最好的前三名
with
t1 as (
select
c.c_id,c.c_name,s.s_id,s.s_name,s_score,row_number() over(partition by c.c_id order by s_score desc) as rank
from score sc
inner join student s on sc.s_id = s.s_id
inner join course c on sc.c_id = c.c_id
)
select * from t1 where rank <= 3;
+------+--------+------+--------+---------+------+
| c_id | c_name | s_id | s_name | s_score | rank |
+------+--------+------+--------+---------+------+
| 1 | 語文 | 1 | 趙雷 | 80 | 1 |
| 1 | 語文 | 3 | 孫風 | 80 | 2 |
| 1 | 語文 | 5 | 周梅 | 76 | 3 |
| 2 | 數學 | 1 | 趙雷 | 90 | 1 |
| 2 | 數學 | 7 | 鄭竹 | 89 | 2 |
| 2 | 數學 | 5 | 周梅 | 87 | 3 |
| 3 | 英語 | 1 | 趙雷 | 99 | 1 |
| 3 | 英語 | 7 | 鄭竹 | 98 | 2 |
| 3 | 英語 | 3 | 孫風 | 80 | 3 |
+------+--------+------+--------+---------+------+
43、統計每門課程的學生選修人數（超過5人的課程才統計）
– 要求輸出課程號和選修人數，查詢結果按人數降序排列，若人數相同，按課程號升序排列
with
t1 as (select c_id,count(*) as cnt_student from score group by c_id having cnt_student > 5)
select c.c_id,cnt_student
from course c
inner join t1 on c.c_id = t1.c_id
order by cnt_student desc,c.c_id;
+------+-------------+
| c_id | cnt_student |
+------+-------------+
| 1 | 6 |
| 2 | 6 |
| 3 | 6 |
+------+-------------+
44、檢索至少選修兩門課程的學生學號
select s_id
from score
group by s_id
having count(*) >= 2;
+------+
| s_id |
+------+
| 1 |
| 2 |
| 3 |
| 4 |
| 5 |
| 6 |
| 7 |
+------+
45、查詢選修了全部課程的學生信息
with
t1 as (select count(*) as cnt_course from course),
t2 as (select s_id,count(*) as cnt_course from score group by s_id having ),
t3 as (select s_id from t1 cross join t2 where t1.cnt_course = t2.cnt_course)
select *
from student s
where exists(select * from t3 where s.s_id = t3.s_id);
+------+--------+------------+-------+
| s_id | s_name | s_birth | s_sex |
+------+--------+------------+-------+
| 1 | 趙雷 | 1990-01-01 | 男 |
| 2 | 錢電 | 1990-12-21 | 男 |
| 3 | 孫風 | 1990-05-20 | 男 |
| 4 | 李雲 | 1990-08-06 | 男 |
+------+--------+------------+-------+
46、查詢各學生的年齡(週歲)
– 按照出生日期來算，當前月日 < 出生年月的月日則，年齡減一
select
s_id,s_name,s_birth,
if (
month(current_date()) < month(s_birth) or (month(current_date()) = month(s_birth) and day(current_date()) < day(s_birth)),
year(current_date()) - year(s_birth) - 1,
year(current_date()) - year(s_birth)
)
as s_age
from student;
47、查詢本週過生日的學生
select *
from student
where
datediff(concat(year(current_date()), date_format(s_birth, '-MM-dd')), to_date(current_date()))
between 0 and 7
or
datediff(concat(year(current_date()) + 1, date_format(s_birth, '-MM-dd')), to_date(current_date()))
between 0 and 7;
48、查詢下週過生日的學生
select *
from student
where
datediff(concat(year(current_date()), date_format(s_birth, '-MM-dd')), to_date(current_date()))
between 7 and 14
or
datediff(concat(year(current_date()) + 1, date_format(s_birth, '-MM-dd')), to_date(current_date()))
between 7 and 14;
49、查詢本月過生日的學生
select *
from student
where month(s_birth) = month(current_date());
50、查詢12月份過生日的學生
select *
from student
where month(s_birth) = 12;
+------+--------+------------+-------+
| s_id | s_name | s_birth | s_sex |
+------+--------+------------+-------+
| 2 | 錢電 | 1990-12-21 | 男 |
| 5 | 周梅 | 1991-12-01 | 女 |
+------+--------+------------+-------+