多條件查詢SQL語句

表结构如下：

–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

--建表SQL

--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);

（一）评分标准：

1. 学习每门课程的学生人数。(3分)

select COUNT(c_name),c_name from course join score on course.c_id=score .c_id join student on score.s_id=student.s_id

1. 查询1990年出生的学生信息。(3分)

select * from student WHERE s_birth=1990

1. 查询同名同姓且同性别的信息及各自的数量。(3分)

select COUNT(s_name&&s_sex),s_name,s_sex from student GROUP BY s_name,s_sex

1. 查询名字中有‘风’字的学生信息。(3分)

select * from student WHERE s_name LIKE '%风'

1. 查询出男生及女生的数量。(3分)

select COUNT(s_sex) from student GROUP BY s_sex='男',s_sex='女'

1. 检索"01"课程分数小于60，按分数降序排列的学生信息。（5分）

select t2.* from score t1,student t2 where t2.s_id = t1.s_id and t1.s_score < '60' and t1.c_id = '01' order by t1.s_score;

1. 查询"01"课程比"02"课程成绩低的学生的信息及课程分数。（5分）

select s1.*,s2.01_score,s2.02_score from student s1,

(select t1.s_id as s_id,t1.s_score

as 01_score,t2.s_score

as 02_score from score t1,score t2

where t1.s_id = t2.s_id

and t1.c_id = '01'

and t2.c_id = '02'

and t1.s_score > t2.s_score ) s2

where s1.s_id = s2.s_id;

1. 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。（5分）

select t1.s_id,t2.s_name,avg(t1.s_score) as avg_score from score t1

left join student t2 on t1.s_id = t2.s_id

group by t1.s_id

having avg(t1.s_score) >= 60

1. 查询学过"张三"老师授课的同学的信息。（5分）

select * from student JOIN score on student.s_id=score.s_id

JOIN course on score.c_id=course.c_id

JOIN teacher on course.t_id=teacher.t_id

WHERE t_name='张三'

1. 查询至少有一门没有考试的学生信息。（5分）

select s_score,s_name,c_name from score JOIN student on student.s_id=score.s_id

JOIN course on course.c_id=score.c_id

WHERE s_score=0

1. 查询所有学生的出生日期及年龄。（5分）

select (YEAR(CURDATE())-YEAR(s_birth)) as age,s_name FROM student

1. 查询半月过生日的学生信息。（5分）

select *,DATE_FORMAT(s_birth,"%d") as day from student as ab inner join score as bb on ab.s_id=bb.s_id join course as cb on bb.c_id=cb.c_id join teacher as db on cb.t_id=db.t_id having day < 15

1. 绩。（10分）

select c_name,student.s_id,s_name,s_score from course JOIN score on course.c_id=score.c_id

JOIN student on student.s_id=score.s_id

WHERE s_score<60

1. 查询各科成绩最高分、最低分和平均分：（10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：>=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 then 1 else 0 end)/ sum(case when a.s_score then 1 else 0 end)), 2) as 中等率,

    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,

    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

from

    score a

left join course b on

    a.c_id = b.c_id

group by

    a.c_id,

    b.c_name

1. 查询学生的总成绩并进行排名（高到低），显示排名数、姓名、性别、学号、总分。（10分）

select s_name,s_sex,student.s_id,SUM(s_score) from course JOIN score on course.c_id=score.c_id

JOIN student on score.s_id=student.s_id GROUP BY s_name

ORDER BY  SUM(s_score) DESC

1. 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。（10分）

select course.c_name, course.c_id,

sum(case when score.s_score<=100 and score.s_score>85 then 1 else 0 end) as "[100-85]",

sum(case when score.s_score<=85 and score.s_score>70 then 1 else 0 end) as "[85-70]",

sum(case when score.s_score<=70 and score.s_score>60 then 1 else 0 end) as "[70-60]",

sum(case when score.s_score<=60 and score.s_score>0 then 1 else 0 end) as "[60-0]"

from score left join course

on score.c_id = course.c_id

group by score.c_id;

1. 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。（10分）

select t5.*,t4.s_score as MAX_score,t4.c_id,t6.c_name

from (score t4,student t5)

right join course t6 on t6.c_id = t4.c_id

where t4.s_score = (select max(t3.s_score)

from teacher t1,course t2,score t3

where t1.t_name = '张三' and t1.t_id = t2.t_id and t2.c_id = t3.c_id)and t4.s_id = t5.s_id