mysql题库,SQL语句练习50题(MySQL版)

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表名和字段

–1.学生表

student(s_id,s_name,s_birth,s_sex) –学生编号,学生姓名, 出生年月,学生性别

–2.课程表

course(c_id,c_name,t_id) – –课程编号, 课程名称, 教师编号

–3.教师表

teacher(t_id,t_name) –教师编号,教师姓名

–4.成绩表

score(s_id,c_id,s_score) –学生编号,课程编号,分数

测试数据

–建表 –学生表 create table `student`( `s_id` varchar(20), `s_name` varchar(20) not null default ”, `s_birth` varchar(20) not null default ”, `s_sex` varchar(10) not null default ”, primary key(`s_id`) ); –课程表 create table `course`( `c_id` varchar(20), `c_name` varchar(20) not null default ”, `t_id` varchar(20) not null, primary key(`c_id`) ); –教师表 create table `teacher`( `t_id` varchar(20), `t_name` varchar(20) not null default ”, primary key(`t_id`) ); –成绩表 create table `score`( `s_id` varchar(20), `c_id` varchar(20), `s_score` int(3), primary key(`s_id`,`c_id`) ); –插入学生表测试数据 insert into student values(’01’ , ‘赵雷’ , ‘1990-01-01’ , ‘男’); insert into student values(’02’ , ‘钱电’ , ‘1990-12-21’ , ‘男’); insert into student values(’03’ , ‘孙风’ , ‘1990-05-20’ , ‘男’); insert into student values(’04’ , ‘李云’ , ‘1990-08-06’ , ‘男’); insert into student values(’05’ , ‘周梅’ , ‘1991-12-01’ , ‘女’); insert into student values(’06’ , ‘吴兰’ , ‘1992-03-01’ , ‘女’); insert into student values(’07’ , ‘郑竹’ , ‘1989-07-01’ , ‘女’); insert into student values(’08’ , ‘王菊’ , ‘1990-01-20’ , ‘女’); –课程表测试数据 insert into course values(’01’ , ‘语文’ , ’02’); insert into course values(’02’ , ‘数学’ , ’01’); insert into course values(’03’ , ‘英语’ , ’03’); –教师表测试数据 insert into teacher values(’01’ , ‘张三’); insert into teacher values(’02’ , ‘李四’); insert into teacher values(’03’ , ‘王五’); –成绩表测试数据 insert into score values(’01’ , ’01’ , 80); insert into score values(’01’ , ’02’ , 90); insert into score values(’01’ , ’03’ , 99); insert into score values(’02’ , ’01’ , 70); insert into score values(’02’ , ’02’ , 60); insert into score values(’02’ , ’03’ , 80); insert into score values(’03’ , ’01’ , 80); insert into score values(’03’ , ’02’ , 80); insert into score values(’03’ , ’03’ , 80); insert into score values(’04’ , ’01’ , 50); insert into score values(’04’ , ’02’ , 30); insert into score values(’04’ , ’03’ , 20); insert into score values(’05’ , ’01’ , 76); insert into score values(’05’ , ’02’ , 87); insert into score values(’06’ , ’01’ , 31); insert into score values(’06’ , ’03’ , 34); insert into score values(’07’ , ’02’ , 89); insert into score values(’07’ , ’03’ , 98);

练习题和sql语句

— 1、查询”01″课程比”02″课程成绩高的学生的信息及课程分数 select a.* ,b.s_score as 01_score,c.s_score as 02_score from student a join score b on a.s_id=b.s_id and b.c_id=’01’ 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 –也可以这样写 select a.*,b.s_score as 01_score,c.s_score as 02_score from student a,score b,score c where a.s_id=b.s_id and a.s_id=c.s_id and b.c_id=’01’ and c.c_id=’02’ and b.s_score>c.s_score — 2、查询”01″课程比”02″课程成绩低的学生的信息及课程分数 select a.* ,b.s_score as 01_score,c.s_score as 02_score from student a left join score b on a.s_id=b.s_id and b.c_id=’01’ or b.c_id=null join score c on a.s_id=c.s_id and c.c_id=’02’ where b.s_score=60; — 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 — (包括有成绩的和无成绩的) select b.s_id,b.s_name,round(avg(a.s_score),2) as avg_score from student b left join score a on b.s_id = a.s_id group by b.s_id,b.s_name having avg_score <60 union select a.s_id,a.s_name,0 as avg_score from student a where a.s_id not in ( select distinct s_id from score); — 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 select a.s_id,a.s_name,count(b.c_id) as sum_course,sum(b.s_score) as sum_score from student a left join score b on a.s_id=b.s_id group by a.s_id,a.s_name; — 6、查询"李"姓老师的数量 select count(t_id) from teacher where t_name like '李%'; — 7、查询学过"张三"老师授课的同学的信息 select a.* from student a join score b on a.s_id=b.s_id where b.c_id in( select c_id from course where t_id =( select t_id from teacher where t_name = '张三')); — 8、查询没学过"张三"老师授课的同学的信息 select * from student c where c.s_id not in( select a.s_id from student a join score b on a.s_id=b.s_id where b.c_id in( select a.c_id from course a join teacher b on a.t_id = b.t_id 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 select a.* from student a,score b,score c where a.s_id = b.s_id and a.s_id = c.s_id and b.c_id='01' and c.c_id='02'; — 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 select a.* from student a 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') — 11、查询没有学全所有课程的同学的信息 –@wendiepei的写法 select s.* from student s left join score s1 on s1.s_id=s.s_id group by s.s_id having count(s1.c_id)<(select count(*) from course) –@k1051785839的写法 select * from student where s_id not in( select s_id from score t1 group by s_id having count(*) =(select count(distinct c_id) from course)) — 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 select * from student where s_id in( 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') ); — 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 –@ouyang_1993的写法 select student.* from student where s_id in (select s_id from score group by s_id having count(s_id) = ( #下面的语句是找到'01'同学学习的课程数 select count(c_id) from score where s_id = '01' ) ) and s_id not in ( #下面的语句是找到学过‘01’同学没学过的课程，有哪些同学。并排除他们 select s_id from score where c_id in( #下面的语句是找到‘01’同学没学过的课程 select distinct c_id from score where c_id not in ( #下面的语句是找出‘01’同学学习的课程 select c_id from score where s_id = '01' ) ) group by s_id ) #下面的条件是排除01同学 and s_id not in ('01') –@k1051785839的写法 select t3.* from ( select s_id, group_concat(c_id order by c_id) group1 from score where s_id ’01’ group by s_id ) t1 inner join ( select group_concat(c_id order by c_id) group2 from score where s_id = ’01’ group by s_id ) t2 on t1.group1 = t2.group2 inner join student t3 on t1.s_id = t3.s_id — 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 ( select s_id from score where c_id = (select c_id from course where t_id =( select t_id from teacher where t_name = ‘张三’))); — 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 select a.s_id,a.s_name,round(avg(b.s_score)) from student a left join score b on a.s_id = b.s_id where a.s_id in( select s_id from score where s_score=2) group by a.s_id,a.s_name — 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 student a,score b where a.s_id = b.s_id and b.c_id=’01’ and b.s_score=60，中等为：70-80，优良为：80-90，优秀为：>=90 select a.c_id,b.c_name,max(s_score),min(s_score),round(avg(s_score),2), 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, round(100*(sum(case when a.s_score>=70 and 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 优秀率 from score a left join course b on a.c_id = b.c_id group by a.c_id,b.c_name — 19、按各科成绩进行排序，并显示排名 — mysql没有rank函数 select a.s_id,a.c_id, @i:=@i +1 as i保留排名, @k:=(case when @score=a.s_score then @k else @i end) as rank不保留排名, @score:=a.s_score as score from ( select s_id,c_id,s_score from score group by s_id,c_id,s_score order by s_score desc )a,(select @k:=0,@i:=0,@score:=0)s –@k1051785839的写法 (select * from (select t1.c_id, t1.s_score, (select count(distinct t2.s_score) from score t2 where t2.s_score>=t1.s_score and t2.c_id=’01’) rank from score t1 where t1.c_id=’01’ order by t1.s_score desc) t1) union (select * from (select t1.c_id, t1.s_score, (select count(distinct t2.s_score) from score t2 where t2.s_score>=t1.s_score and t2.c_id=’02’) rank from score t1 where t1.c_id=’02’ order by t1.s_score desc) t2) union (select * from (select t1.c_id, t1.s_score, (select count(distinct t2.s_score) from score t2 where t2.s_score>=t1.s_score and t2.c_id=’03’) rank from score t1 where t1.c_id=’03’ order by t1.s_score desc) t3) — 20、查询学生的总成绩并进行排名 select a.s_id, @i:=@i+1 as i, @k:=(case when @score=a.sum_score then @k else @i end) as rank, @score:=a.sum_score as score from (select s_id,sum(s_score) as sum_score from score group by s_id order by sum_score desc)a, (select @k:=0,@i:=0,@score:=0)s — 21、查询不同老师所教不同课程平均分从高到低显示 select a.t_id,c.t_name,a.c_id,round(avg(s_score),2) as avg_score from course a left join score b on a.c_id=b.c_id left join teacher c on a.t_id=c.t_id 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 select d.*,c.排名,c.s_score,c.c_id from ( 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’ order by a.s_score desc )c left join student d on c.s_id=d.s_id where 排名 between 2 and 3 union select d.*,c.排名,c.s_score,c.c_id from ( 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’ order by a.s_score desc )c left join student d on c.s_id=d.s_id where 排名 between 2 and 3 union select d.*,c.排名,c.s_score,c.c_id from ( 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’ order by a.s_score desc )c left join student d on c.s_id=d.s_id where 排名 between 2 and 3; — 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 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 left join (select c_id,sum(case when s_score >85 and s_score 85 and s_score 70 and s_score 70 and s_score 60 and s_score 60 and s_score =0 and s_score =0 and s_score <=60 then 1 else 0 end)/count(*)),2) as 百分比 from score group by c_id)e on a.c_id=e.c_id left join course f on a.c_id = f.c_id — 24、查询学生平均成绩及其名次 select a.s_id, @i:=@i+1 as '不保留空缺排名', @k:=(case when @avg_score=a.avg_s then @k else @i end) as '保留空缺排名', @avg_score:=avg_s as '平均分' from (select s_id,round(avg(s_score),2) as avg_s from score group by s_id order by avg_s desc)a,(select @avg_score:=0,@i:=0,@k:=0)b; — 25、查询各科成绩前三名的记录 — 1.选出b表比a表成绩大的所有组 — 2.选出比当前id成绩大的 小于三个的 select a.s_id,a.c_id,a.s_score from score a left join score b on a.c_id = b.c_id and a.s_score<b.s_score group by a.s_id,a.c_id,a.s_score having count(b.s_id)=85 — 34、查询课程名称为”数学”，且分数低于60的学生姓名和分数 select a.s_name,b.s_score from score b join student a on a.s_id=b.s_id where b.c_id=( select c_id from course where c_name =’数学’) and b.s_score=70 — 37、查询不及格的课程 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 where a.s_score80 — 39、求每门课程的学生人数 select count(*) from score group by c_id; — 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 — 查询老师id select c_id from course c,teacher d where c.t_id=d.t_id and d.t_name=’张三’ — 查询最高分（可能有相同分数） select max(s_score) from score where c_id=’02’ — 查询信息 select a.*,b.s_score,b.c_id,c.c_name from student a left join score b on a.s_id = b.s_id left join course c on b.c_id=c.c_id 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’) and b.s_score in (select max(s_score) from score where c_id=’02’) — 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 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 — 42、查询每门功成绩最好的前两名 — 牛逼的写法 select a.s_id,a.c_id,a.s_score from score a where (select count(1) from score b where b.c_id=a.c_id and b.s_score>=a.s_score)5 order by total,c_id asc — 44、检索至少选修两门课程的学生学号 select s_id,count(*) as sel from score group by s_id having sel>=2 — 45、查询选修了全部课程的学生信息 select * from student where s_id in( select s_id from score group by s_id having count(*)=(select count(*) from course)) — 46、查询各学生的年龄 — 按照出生日期来算，当前月日 date_format(s_birth,’%m%d’) then 0 else 1 end)) as age from student; — 47、查询本周过生日的学生 select * from student where week(date_format(now(),’%y%m%d’))=week(s_birth) select * from student where yearweek(s_birth)=yearweek(date_format(now(),’%y%m%d’)) select week(date_format(now(),’%y%m%d’)) — 48、查询下周过生日的学生 select * from student where week(date_format(now(),’%y%m%d’))+1 =week(s_birth) — 49、查询本月过生日的学生 select * from student where month(date_format(now(),’%y%m%d’)) =month(s_birth) — 50、查询下月过生日的学生 select * from student where month(date_format(now(),’%y%m%d’))+1 =month(s_birth)

原文：
https://mp.weixin.qq.com/s/xiu3jrif8ktt8jxr3vlqtw

作者：java资源库

来源：微信公众号