hive 练习

  1 练习题和sql语句
  2 
  3 基础sql语句
  4 
  5 统计每个学生的总分。
  6 统计出学号和总分
  7    select s_id , sum(s_score) as zf  from  score  group  by s_id
  8  
  9 上表结果和stuent做join连接
 10 
 11 select stu.s_name,zf.ss from
 12  
 13 (select s_id , sum(s_score) as ss from score group by s_id) as  zf
 14  
 15 Join
 16  
 17 student  as stu
 18  
 19 on  stu.s_id=zf.s_id;
 20 2.查询表中所有学生的姓名和对应的英语成绩。
 21 
 22 select stu.s_name,c.c_name,s.s_score from
 23  
 24      score as s 
 25  
 26      join
 27  
 28      course as c
 29  
 30      on s.c_id=c.c_id
 31  
 32      join
 33  
 34      student as stu
 35  
 36      on stu.s_id = s.s_id
 37  
 38      where
 39  
 40      c.c_name = ‘english‘;
 41 3. 在所有学生总分数上加10分特长分。
 42 
 43 关键代码
 44 
 45   select s_id,sum(s_score)+10 from score group by s_id;
 46  
 47 查询姓名为liyun的学生总成绩
 48  select sum(s_score) from score where  s_id in (select s_id from student where        s_name=‘liyun‘);
 49  
 50 查询英语成绩大于90分的同学
 51 
 52  
 53 
 54 8.查询总分大于270分的所有同学
 55 
 56  
 57 
 58 查询英语分数在 80－90之间的同学。
 59  
 60 
 61 查询数学分数为89,90,91的同学。
 62  
 63 
 64 查询所有姓li的学生平均成绩。
 65  
 66 
 67 查询数学分>80，语文分>80的同学。
 68  
 69 
 70 对数学成绩排序后输出。
 71  
 72 
 73 对总分排序后输出，然后再按从高到低的顺序输出
 74  
 75 
 76  对姓li的学生数学成绩排序输出
 77  
 78 
 79  
 80 
 81 有一定难度的sql语句
 82 
 83 
 84  
 85 -- 1、查询"01"课程比"02"课程成绩高的学生的信息及课程分数  
 86 思路：
 87 关键步骤：
 88 select * from score l join score r on (l.s_id = r.s_id and l.c_id=2 and r.c_id=1); 
 89  
 90 select a.* ,b.s_score as 01_score,c.s_score as 02_score from 
 91     student a 
 92     join score b on a.s_id=b.s_id and b.c_id=‘01‘
 93     left join score c on a.s_id=c.s_id and c.c_id=‘02‘ or c.c_id = NULL where b.s_score>c.s_score
 94 -- 2、查询"01"课程比"02"课程成绩低的学生的信息及课程分数
 95 select a.* ,b.s_score as 01_score,c.s_score as 02_score from 
 96     student a left join score b on a.s_id=b.s_id and b.c_id=‘01‘ or b.c_id=NULL 
 97      join score c on a.s_id=c.s_id and c.c_id=‘02‘ where b.s_score<c.s_score
 98 -- 3、查询平均成绩大于等于60分的同学的学生编号和学生姓名和平均成绩
 99 select b.s_id,b.s_name,ROUND(AVG(a.s_score),2) as avg_score from 
100     student b 
101     join score a on b.s_id = a.s_id
102     GROUP BY b.s_id,b.s_name HAVING ROUND(AVG(a.s_score),2)>=60;
103 -- 4、查询平均成绩小于60分的同学的学生编号和学生姓名和平均成绩
104 -- (包括有成绩的和无成绩的)
105 select b.s_id,b.s_name,ROUND(AVG(a.s_score),2) as avg_score from 
106     student b 
107     left join score a on b.s_id = a.s_id
108     GROUP BY b.s_id,b.s_name HAVING ROUND(AVG(a.s_score),2)<60
109     unionselect a.s_id,a.s_name,0 as avg_score from 
110     student a 
111     where a.s_id not in (
112                 select distinct s_id from score);
113 -- 5、查询所有同学的学生编号、学生姓名、选课总数、所有课程的总成绩
114 select a.s_id,a.s_name,count(b.c_id) as sum_course,sum(b.s_score) as sum_score from 
115     student a 
116     left join score b on a.s_id=b.s_id
117     GROUP BY a.s_id,a.s_name;
118 -- 6、查询"李"姓老师的数量 
119 select a.* from 
120     student a 
121     join score b on a.s_id=b.s_id where b.c_id in(
122         select c_id from course where t_id =(
123             select t_id from teacher where t_name = ‘张三‘));
124 -- 7、查询学过"张三"老师授课的同学的信息 
125 select a.* from 
126     student a 
127     join score b on a.s_id=b.s_id where b.c_id in(
128         select c_id from course where t_id =(
129             select t_id from teacher where t_name = ‘张三‘));
130 -- 8、查询没学过"张三"老师授课的同学的信息 
131  select * from student c 
132     where c.s_id not in(
133         select a.s_id from student a join score b on a.s_id=b.s_id where b.c_id in(
134             select c_id from course where t_id =(
135                 select t_id from teacher where t_name = ‘张三‘)));-- 9、查询学过编号为"01"并且也学过编号为"02"的课程的同学的信息
136 select a.* from 
137     student a,score b,score c 
138     where a.s_id = b.s_id  and a.s_id = c.s_id and b.c_id=‘01‘ and c.c_id=‘02‘;
139 -- 10、查询学过编号为"01"但是没有学过编号为"02"的课程的同学的信息
140 select a.* from 
141     student a 
142     where a.s_id in (select s_id from score where c_id=‘01‘ ) and a.s_id not in(select s_id from score where c_id=‘02‘)
143 -- 11、查询没有学全所有课程的同学的信息 
144 select s.* from 
145     student s where s.s_id in(
146         select s_id from score where s_id not in(
147             select a.s_id from score a 
148                 join score b on a.s_id = b.s_id and b.c_id=‘02‘
149                 join score c on a.s_id = c.s_id and c.c_id=‘03‘
150             where a.c_id=‘01‘))
151 -- 12、查询至少有一门课与学号为"01"的同学所学相同的同学的信息 
152 select * from student where s_id in(
153     select distinct a.s_id from score a where a.c_id in(select a.c_id from score a where a.s_id=‘01‘)
154     );
155 -- 13、查询和"01"号的同学学习的课程完全相同的其他同学的信息 
156 select a.* from student a where a.s_id in(
157     select distinct s_id from score where s_id!=‘01‘ and c_id in(select c_id from score where s_id=‘01‘)
158     group by s_id 
159     having count(1)=(select count(1) from score where s_id=‘01‘));-- 14、查询没学过"张三"老师讲授的任一门课程的学生姓名 select a.s_name from student a where a.s_id not in (
160     select s_id from score where c_id = 
161                 (select c_id from course where t_id =(
162                     select t_id from teacher where t_name = ‘张三‘)) 
163                 group by s_id);
164 -- 15、查询两门及其以上不及格课程的同学的学号，姓名及其平均成绩
165  select a.s_id,a.s_name,ROUND(AVG(b.s_score)) from 
166     student a 
167     left join score b on a.s_id = b.s_id
168     where a.s_id in(
169             select s_id from score where s_score<60 GROUP BY  s_id having count(1)>=2)
170     GROUP BY a.s_id,a.s_name
171 -- 16、检索"01"课程分数小于60，按分数降序排列的学生信息select a.*,b.c_id,b.s_score from 
172  student a,score b 
173     where a.s_id = b.s_id and b.c_id=‘01‘ and b.s_score<60 ORDER BY b.s_score DESC;
174 -- 17、按平均成绩从高到低显示所有学生的所有课程的成绩以及平均成绩
175 select a.s_id,(select s_score from score where s_id=a.s_id and c_id=‘01‘) as 语文,
176                 (select s_score from score where s_id=a.s_id and c_id=‘02‘) as 数学,
177                 (select s_score from score where s_id=a.s_id and c_id=‘03‘) as 英语,
178             round(avg(s_score),2) as 平均分 from score a  GROUP BY a.s_id ORDER BY 平均分 DESC;
179 -- 18.查询各科成绩最高分、最低分和平均分：以如下形式显示：课程ID，课程name，最高分，最低分，平均分，及格率，中等率，优良率，优秀率--及格为>=60，中等为：70-80，优良为：80-90，优秀为：>=90select 
180 a.c_id,b.c_name,MAX(s_score),MIN(s_score),ROUND(AVG(s_score),2),
181     ROUND(100*(SUM(case when a.s_score>=60 then 1 else 0 end)/SUM(case when a.s_score then 1 else 0 end)),2) as 及格率,
182     ROUND(100*(SUM(case when a.s_score>=70 and a.s_score<=80 then 1 else 0 end)/SUM(case when a.s_score then 1 else 0 end)),2) as 中等率,
183     ROUND(100*(SUM(case when a.s_score>=80 and a.s_score<=90 then 1 else 0 end)/SUM(case when a.s_score then 1 else 0 end)),2) as 优良率,
184     ROUND(100*(SUM(case when a.s_score>=90 then 1 else 0 end)/SUM(case when a.s_score then 1 else 0 end)),2) as 优秀率
185     from score a left join course b on a.c_id = b.c_id GROUP BY a.c_id,b.c_name
186 -- 19、按各科成绩进行排序，并显示排名(实现不完全)
187 -- mysql没有rank函数
188     select a.s_id,a.c_id,
189         @i:=@i +1 as i保留排名,
190         @k:=(case when @score=a.s_score then @k else @i end) as rank不保留排名,
191         @score:=a.s_score as score
192     from (
193         select s_id,c_id,s_score from score WHERE c_id=‘01‘ GROUP BY s_id,c_id,s_score ORDER BY s_score DESC
194 )a,(select @k:=0,@i:=0,@score:=0)s
195     union
196     select a.s_id,a.c_id,
197         @i:=@i +1 as i,
198         @k:=(case when @score=a.s_score then @k else @i end) as rank,
199         @score:=a.s_score as score
200     from (
201         select s_id,c_id,s_score from score WHERE c_id=‘02‘ GROUP BY s_id,c_id,s_score ORDER BY s_score DESC
202 )a,(select @k:=0,@i:=0,@score:=0)s
203     union
204     select a.s_id,a.c_id,
205         @i:=@i +1 as i,
206         @k:=(case when @score=a.s_score then @k else @i end) as rank,
207         @score:=a.s_score as score
208     from (
209         select s_id,c_id,s_score from score WHERE c_id=‘03‘ GROUP BY s_id,c_id,s_score ORDER BY s_score DESC
210 )a,(select @k:=0,@i:=0,@score:=0)s
211 -- 20、查询学生的总成绩并进行排名select a.s_id,
212  @i:=@i+1 as i,
213     @k:=(case when @score=a.sum_score then @k else @i end) as rank,
214     @score:=a.sum_score as scorefrom (select s_id,SUM(s_score) as sum_score from score GROUP BY s_id ORDER BY sum_score DESC)a,
215     (select @k:=0,@i:=0,@score:=0)s
216 -- 21、查询不同老师所教不同课程平均分从高到低显示 
217  select a.t_id,c.t_name,a.c_id,ROUND(avg(s_score),2) as avg_score from course a
218         left join score b on a.c_id=b.c_id 
219         left join teacher c on a.t_id=c.t_id
220         GROUP BY a.c_id,a.t_id,c.t_name ORDER BY avg_score DESC;-- 22、查询所有课程的成绩第2名到第3名的学生信息及该课程成绩
221  
222             
223 select d.*,c.排名,c.s_score,c.c_id from (
224                 select a.s_id,a.s_score,a.c_id,@i:=@i+1 as 排名 from score a,(select @i:=0)s where a.c_id=‘01‘    
225             )c
226             left join student d on c.s_id=d.s_id
227             where 排名 BETWEEN 2 AND 3
228             UNION
229             select d.*,c.排名,c.s_score,c.c_id from (
230                 select a.s_id,a.s_score,a.c_id,@j:=@j+1 as 排名 from score a,(select @j:=0)s where a.c_id=‘02‘    
231             )c
232             left join student d on c.s_id=d.s_id
233             where 排名 BETWEEN 2 AND 3
234             UNION
235             select d.*,c.排名,c.s_score,c.c_id from (
236                 select a.s_id,a.s_score,a.c_id,@k:=@k+1 as 排名 from score a,(select @k:=0)s where a.c_id=‘03‘    
237             )c
238             left join student d on c.s_id=d.s_id
239             where 排名 BETWEEN 2 AND 3;
240 -- 23、统计各科成绩各分数段人数：课程编号,课程名称,[100-85],[85-70],[70-60],[0-60]及所占百分比
241 select distinct f.c_name,a.c_id,b.`85-100`,b.百分比,c.`70-85`,c.百分比,d.`60-70`,d.百分比,e.`0-60`,e.百分比 from score a
242                 left join (select c_id,SUM(case when s_score >85 and s_score <=100 then 1 else 0 end) as `85-100`,
243                                             ROUND(100*(SUM(case when s_score >85 and s_score <=100 then 1 else 0 end)/count(*)),2) as 百分比
244                                 from score GROUP BY c_id)b on a.c_id=b.c_id
245                 left join (select c_id,SUM(case when s_score >70 and s_score <=85 then 1 else 0 end) as `70-85`,
246                                             ROUND(100*(SUM(case when s_score >70 and s_score <=85 then 1 else 0 end)/count(*)),2) as 百分比
247                                 from score GROUP BY c_id)c on a.c_id=c.c_id
248                 left join (select c_id,SUM(case when s_score >60 and s_score <=70 then 1 else 0 end) as `60-70`,
249                                             ROUND(100*(SUM(case when s_score >60 and s_score <=70 then 1 else 0 end)/count(*)),2) as 百分比
250                                 from score GROUP BY c_id)d on a.c_id=d.c_id
251                 left join (select c_id,SUM(case when s_score >=0 and s_score <=60 then 1 else 0 end) as `0-60`,
252                                             ROUND(100*(SUM(case when s_score >=0 and s_score <=60 then 1 else 0 end)/count(*)),2) as 百分比
253                                 from score GROUP BY c_id)e on a.c_id=e.c_id
254                 left join course f on a.c_id = f.c_id
255 -- 24、查询学生平均成绩及其名次 
256   select a.s_id,
257                 @i:=@i+1 as ‘不保留空缺排名‘,
258                 @k:=(case when @avg_score=a.avg_s then @k else @i end) as ‘保留空缺排名‘,
259                 @avg_score:=avg_s as ‘平均分‘
260         from (select s_id,ROUND(AVG(s_score),2) as avg_s from score GROUP BY s_id)a,(select @avg_score:=0,@i:=0,@k:=0)b;
261 
262 -- 25、查询各科成绩前三名的记录    
263 -- 1.选出b表比a表成绩大的所有组       
264 -- 2.选出比当前id成绩大的 小于三个的
265 select a.s_id,a.c_id,a.s_score from score a 
266             left join score b on a.c_id = b.c_id and a.s_score<b.s_score
267             group by a.s_id,a.c_id,a.s_score HAVING COUNT(b.s_id)<3
268             ORDER BY a.c_id,a.s_score DESC
269 -- 26、查询每门课程被选修的学生数
270  select c_id,count(s_id) from score a GROUP BY c_id
271 -- 27、查询出只有两门课程的全部学生的学号和姓名 
272   select s_id,s_name from student where s_id in(
273                 select s_id from score GROUP BY s_id HAVING COUNT(c_id)=2);
274 -- 28、查询男生、女生人数 
275 select s_sex,COUNT(s_sex) as 人数  from student GROUP BY s_sex
276 -- 29、查询名字中含有"风"字的学生信息
277  select * from student where s_name like ‘%风%‘;
278 -- 30、查询同名同性学生名单，并统计同名人数 
279 select a.s_name,a.s_sex,count(*) from student a  JOIN 
280                     student b on a.s_id !=b.s_id and a.s_name = b.s_name and a.s_sex = b.s_sex
281         GROUP BY a.s_name,a.s_sex
282 -- 31、查询1990年出生的学生名单
283  select s_name from student where s_birth like ‘1990%‘
284 -- 32、查询每门课程的平均成绩，结果按平均成绩降序排列，平均成绩相同时，按课程编号升序排列 
285 select c_id,ROUND(AVG(s_score),2) as avg_score from score GROUP BY c_id ORDER BY avg_score DESC,c_id ASC
286 -- 33、查询平均成绩大于等于85的所有学生的学号、姓名和平均成绩 
287     select a.s_id,b.s_name,ROUND(avg(a.s_score),2) as avg_score from score a
288         left join student b on a.s_id=b.s_id GROUP BY s_id HAVING avg_score>=85
289 -- 34、查询课程名称为"数学"，且分数低于60的学生姓名和分数 
290  
291         select a.s_name,b.s_score from score b LEFT JOIN student a on a.s_id=b.s_id where b.c_id=(
292                     select c_id from course where c_name =‘数学‘) and b.s_score<60
293 
294  
295 -- 35、查询所有学生的课程及分数情况； 
296 select a.s_id,a.s_name,
297                     SUM(case c.c_name when ‘语文‘ then b.s_score else 0 end) as ‘语文‘,
298                     SUM(case c.c_name when ‘数学‘ then b.s_score else 0 end) as ‘数学‘,
299                     SUM(case c.c_name when ‘英语‘ then b.s_score else 0 end) as ‘英语‘,
300                     SUM(b.s_score) as  ‘总分‘
301         from student a left join score b on a.s_id = b.s_id 
302         left join course c on b.c_id = c.c_id 
303         GROUP BY a.s_id,a.s_name
304  -- 36、查询任何一门课程成绩在70分以上的姓名、课程名称和分数；
305    select a.s_name,b.c_name,c.s_score from course b left join score c on b.c_id = c.c_id
306                 left join student a on a.s_id=c.s_id where c.s_score>=70
307 -- 37、查询不及格的课程
308  select a.s_id,a.c_id,b.c_name,a.s_score from score a left join course b on a.c_id = b.c_id
309             where a.s_score<60 
310 --38、查询课程编号为01且课程成绩在80分以上的学生的学号和姓名；
311 select a.s_id,b.s_name from score a LEFT JOIN student b on a.s_id = b.s_id
312             where a.c_id = ‘01‘ and a.s_score>80
313 -- 39、求每门课程的学生人数 
314         select count(*) from score GROUP BY c_id;
315 
316 -- 40、查询选修"张三"老师所授课程的学生中，成绩最高的学生信息及其成绩
317 -- 查询老师id   
318         
319 select c_id from course c,teacher d where c.t_id=d.t_id and d.t_name=‘张三‘
320         -- 查询最高分（可能有相同分数）
321         select MAX(s_score) from score where c_id=‘02‘
322         -- 查询信息
323         select a.*,b.s_score,b.c_id,c.c_name from student a
324             LEFT JOIN score b on a.s_id = b.s_id
325             LEFT JOIN course c on b.c_id=c.c_id
326             where b.c_id =(select c_id from course c,teacher d where c.t_id=d.t_id and d.t_name=‘张三‘)
327             and b.s_score in (select MAX(s_score) from score where c_id=‘02‘)
328 -- 41、查询不同课程成绩相同的学生的学生编号、课程编号、学生成绩 
329 select DISTINCT b.s_id,b.c_id,b.s_score from score a,score b where a.c_id != b.c_id and a.s_score = b.s_score
330 -- 42、查询每门功成绩最好的前两名 
331 -- 牛逼的写法
332     select a.s_id,a.c_id,a.s_score from score a
333         where (select COUNT(1) from score b where b.c_id=a.c_id and b.s_score>=a.s_score)<=2 ORDER BY a.c_id
334 -- 43、统计每门课程的学生选修人数（超过5人的课程才统计）。要求输出课程号和选修人数，查询结果按人数降序排列，若人数相同，按课程号升序排列  
335         select c_id,count(*) as total from score GROUP BY c_id HAVING total>5 ORDER BY total,c_id ASC
336 -- 44、检索至少选修两门课程的学生学号 
337         select s_id,count(*) as sel from score GROUP BY s_id HAVING sel>=2
338 -- 45、查询选修了全部课程的学生信息  
339 select * from student where s_id in(        
340             select s_id from score GROUP BY s_id HAVING count(*)=(select count(*) from course))
341 --46、查询各学生的年龄
342 -- 按照出生日期来算，当前月日 < 出生年月的月日则，年龄减一
343  
344     select s_birth,(DATE_FORMAT(NOW(),‘%Y‘)-DATE_FORMAT(s_birth,‘%Y‘) - 
345                 (case when DATE_FORMAT(NOW(),‘%m%d‘)>DATE_FORMAT(s_birth,‘%m%d‘) then 0 else 1 end)) as age
346         from student;
347 -- 47、查询本周过生日的学生
348     
349 select * from student where WEEK(DATE_FORMAT(NOW(),‘%Y%m%d‘))=WEEK(s_birth)
350     select * from student where YEARWEEK(s_birth)=YEARWEEK(DATE_FORMAT(NOW(),‘%Y%m%d‘))
351  
352     select WEEK(DATE_FORMAT(NOW(),‘%Y%m%d‘))
353 -- 48、查询下周过生日的学生
354     select * from student where WEEK(DATE_FORMAT(NOW(),‘%Y%m%d‘))+1 =WEEK(s_birth)
355 -- 49、查询本月过生日的学生
356     select * from student where MONTH(DATE_FORMAT(NOW(),‘%Y%m%d‘)) =MONTH(s_birth)
357 -- 50、查询下月过生日的学生
358     select * from student where MONTH(DATE_FORMAT(NOW(),‘%Y%m%d‘))+1 =MONTH(s_birth)
359