Oracle数据库练习题

题目：设计以下表，完成相关问题SQL编写。
学生表 student (sno,sname,sage,ssex)
课程表 course (cno,cname,tno)
成绩表 sc (sno,cno,grade)
教师表 teacher(tno,tname)
问题：
1.查询课程1的成绩比课程2的成绩高的所有学生的学号
2.查询平均成绩大于70分的同学的学号和平均成绩
3.查询所有同学的学号、姓名、选课数、总成绩
4.查询姓“张”老师的个数
5.查询没学过“张甲”老师课的同学的学号和姓名
6.查询同时学过课程1和课程2的同学的学号和姓名
7.查询学过“李丁”老师所教的所有课程的所有同学的学号和姓名
8.查询课程编号1的成绩比课程编号2的成绩高的所有同学的学号和姓名
9.查询至少有一门课程与学号为1的同学所学课程相同的同学的学号和姓名

表结构及数据如下：

学生表 student (sno,sname,sage,ssex)

原始数据

课程表 course (cno,cname,tno)


成绩表 sc (sno,cno,grade)


教师表 teacher(tno,tname)

1.查询课程1的成绩比课程2的成绩高的所有学生的学号

SELECT
    c1.sno as "学号"
FROM
    (     SELECT
        t.*    
    FROM
        sc t    
    WHERE
        t.cno = 1  ) c1,
    (         SELECT
        c.*        
    FROM
        sc c        
    WHERE
        c.cno = 2    ) c2
WHERE
    c1.sno = c2.sno       
    AND c1.grade > c2.grade

2.查询平均成绩大于70分的同学的学号和平均成绩

SELECT
    sno,
    AVG(grade)
FROM
    sc
GROUP BY
    sno
HAVING
    AVG(grade) > 70

3.查询所有同学的学号、姓名、选课数、总成绩

SELECT
    z."学号",
    g.sname AS "姓名",
    z."选课数",
    z."总分数"
FROM
    (     SELECT
        s.sno AS "学号",
        COUNT(s.cno) AS "选课数",
        SUM(s.grade) AS "总分数"    
    FROM
        course c,
        sc s    
    WHERE
        c.cno = s.cno    
    GROUP BY
        s.sno    
    ORDER BY
        "总分数" DESC ) z,
    student g
WHERE
    z."学号" = g.sno

4.查询姓“张”老师的个数

SELECT
    COUNT(1) AS "个数"
FROM
    teacher
WHERE
    tname LIKE '张%'

5.查询没学过“张甲”老师课的同学的学号和姓名

SELECT
    sno AS "学号",
    sname AS "姓名"
FROM
    student
WHERE
    sno NOT IN (
        SELECT
            g.sno    
        FROM
            sc s,
            student g    
        WHERE
            s.cno IN (
                SELECT
                    c.cno            
                FROM
                    course c,
                    teacher t            
                WHERE
                    c.tno = t.tno                
                    AND t.tname = '张甲'        
            )        
            AND s.sno = g.sno
        )

6.查询同时学过课程1和课程2的同学的学号和姓名

SELECT
    g.sno AS "学号",
    g.sname AS "姓名"
FROM
    student g,
    (   SELECT
        *  
    FROM
        sc  
    WHERE
        cno = 1 ) t
WHERE
    t.sno IN (
        SELECT
            sno    
        FROM
            sc    
        WHERE
            cno = 2  
    )  
    AND g.sno = t.sno

7.查询学过“李丁”老师所教的所有课程的所有同学的学号和姓名

SELECT
    sno AS "学号",
    sname AS "姓名"
FROM
    student
WHERE
    sno in     (
        SELECT
            p.sno    
        FROM
            (SELECT
                *        
            FROM
                sc        
            WHERE
                cno=4) p,
            (SELECT
                *            
            FROM
                sc            
            WHERE
                cno=5) k            
        WHERE
            p.sno=k.sno
        )

8.查询课程编号1的成绩比课程编号2的成绩高的所有同学的学号和姓名

SELECT
    g.sno AS "学号",
    g.sname AS "姓名"
FROM
    student g,
    (SELECT
        *    
    FROM
        sc    
    WHERE
        cno=1) g1,
    (SELECT
        *    
    FROM
        sc    
    WHERE
        cno=2) g2
WHERE
    g1.sno=g2.sno        
    AND g1.grade>g2.grade        
    AND g1.sno=g.sno

9.查询至少有一门课程与学号为1的同学所学课程相同的同学的学号和姓名

SELECT
    DISTINCT g1.sno AS "学号",
    g1.sname AS "姓名"
FROM
    student g1,
    sc g2
WHERE
    g1.sno=g2.sno       
    AND g2.cno in     (
        SELECT
            cno   
        FROM
            sc   
        WHERE
            sno=1
    )