/*查询每门课的平均成绩*/
SELECT cno,AVG(degree) FROM score GROUP BY cno;
/*查询Score表中至少有5名学生选修的并以3开头的课程的平均分数*/
SELECT AVG(degree) FROM score WHERE cno=(
SELECT cno FROM score GROUP BY cno
HAVING COUNT(*)>5 AND cno LIKE '3%'
)
/*查询分数大于70，小于90的Sno列*/
SELECT sno FROM score WHERE degree>70 AND degree<90;
/*查询所有学生的Sname、Cno和Degree列*/
SELECT sname,cno,degree FROM score JOIN student ON score.`sno`=student.sno;
/*查询所有学生的Sno、Cname和Degree列*/
SELECT student.sno,cname,degree FROM score JOIN student ON score.`sno`=student.`sno` JOIN course ON score.`cno`=course.`cno`
/*查询所有学生的Sname、Cname和Degree列*/
SELECT sname,cname,degree FROM score JOIN student ON score.`sno`=student.`sno` JOIN course ON score.`cno`=course.`cno`
/*查询“95033”班学生的平均分*/
SELECT AVG(degree) FROM score JOIN student ON score.`sno`=student.`sno` GROUP BY class
HAVING class='95033'
/*查询选修“3-105”课程的成绩高于“109”号同学成绩的所有同学的记录*/
SELECT * FROM score JOIN student ON score.`sno`=student.`sno`
WHERE degree>(SELECT degree FROM score WHERE sno='109' AND cno='3-105') AND cno='3-105';
/*查询score中选学多门课程的同学中分数为非最高分成绩的记录*/
SELECT * FROM score GROUP BY sno
HAVING degree NOT IN (
SELECT MAX(degree) FROM score GROUP BY cno
)
/*查询和学号为108的同学同年出生的所有学生的Sno、Sname和Sbirthday列*/
SELECT sno,sname,sbirthday FROM student WHERE sbirthday LIKE '1977%';
/*查询“张旭“教师任课的学生成绩（姓名）*/
SELECT sno,degree FROM score WHERE cno=(
SELECT cno FROM course WHERE tno=(
SELECT tno FROM teacher WHERE teacher.`tname`='张旭'
)
)
/*查询考计算机导论的学生成绩*/
SELECT sno,degree FROM score JOIN course ON score.`cno`=course.`cno`
WHERE cname='计算机导论'
/*查询李诚老师教的课程名称*/
SELECT cname FROM course WHERE tno=(
SELECT tno FROM teacher WHERE tname='李诚'
)
/*教高等数学的老师是哪个系的*/
SELECT depart FROM teacher WHERE tno=(
SELECT tno FROM course WHERE cname='高等数学'
)
/*查询选修某课程的同学人数多于5人的教师姓名*/
SELECT teacher.`tname` FROM course JOIN teacher ON course.`tno`=teacher.`tno`
WHERE cno = (
SELECT course.cno FROM score JOIN student ON score.`sno`=student.`sno`
JOIN course ON score.`cno`=course.`cno`
GROUP BY course.`cno`
HAVING COUNT(*)>5
)
/*查询95033班和95031班全体学生的记录*/
SELECT * FROM score JOIN student ON score.`sno`=student.`sno`
JOIN course ON score.`cno`=course.`cno`
/*查询存在有85分以上成绩的课程Cno*/
SELECT course.cno FROM score JOIN course ON score.`cno`=course.`cno` WHERE degree>85
/*查询出“计算机系“教师所教课程的成绩表*/
SELECT degree FROM score WHERE cno IN(
SELECT cno FROM course JOIN teacher ON course.`tno`=teacher.`tno` WHERE depart='计算机系'
)
/*查询选修编号为“3-105“课程且成绩至少高于选修编号为“3-245”的同学
的Cno、Sno和Degree,并按Degree从高到低次序排序*/
SELECT * FROM score WHERE cno='3-105' AND degree>(
SELECT MAX(degree) FROM score WHERE cno='3-245'
) ORDER BY degree DESC
/*查询选修编号为“3-105”且成绩高于选修编号为“3-245”课程的同学
的Cno、Sno和Degree*/
SELECT * FROM score WHERE cno='3-105' AND degree>(
SELECT MAX(degree) FROM score WHERE cno='3-245'
)
/*查询所有教师和同学的name、sex和birthday*/
SELECT * FROM student JOIN score ON student.`sno`=score.`sno`
JOIN course ON score.`cno`=course.`cno`
JOIN teacher ON course.`tno`=teacher.`tno`
SELECT * FROM student
/*查询所有“女”教师和“女”同学的name、sex和birthday*/
SELECT * FROM score JOIN student ON score.`sno`=student.`sno`
JOIN course ON score.`cno`=course.`cno`
JOIN teacher ON course.`tno`=teacher.`tno`
WHERE (ssex='女'AND tsex<>'男') OR (tsex='女' AND ssex<>'男')
/*查询成绩比该课程平均成绩低的同学的成绩表*/
SELECT * FROM score WHERE (cno='3-105'AND degree<(SELECT AVG(degree) FROM score GROUP BY cno HAVING cno='3-105'))
OR(cno='3-245'AND degree<(SELECT AVG(degree) FROM score GROUP BY cno HAVING cno='3-245'))
OR(cno='6-166'AND degree<(SELECT AVG(degree) FROM score GROUP BY cno HAVING cno='6-166'))
/*查询所有任课教师的Tname和Depart*/
SELECT tname,depart FROM course JOIN teacher ON course.`tno`=teacher.`tno`
/*查询所有未讲课的教师的Tname和Depart*/
SELECT tname,depart FROM teacher WHERE teacher.`tno` NOT IN (
SELECT course.`tno` FROM course JOIN teacher ON course.`tno`=teacher.`tno`
)
/*查询至少有2名男生的班号*/
SELECT class FROM student GROUP BY class
HAVING COUNT(*)>=2
/*查询Student表中不姓“王”的同学记录*/
SELECT * FROM student WHERE sname NOT IN (
SELECT sname FROM student WHERE sname LIKE '王%'
)
/*查询Student表中每个学生的姓名和年龄*/
SELECT sname,YEAR(NOW())-YEAR(sbirthday) AS age FROM student
/*查询Student表中最大和最小的Sbirthday日期值*/
SELECT MAX(sbirthday),MIN(sbirthday) FROM student
/*以班号和年龄从大到小的顺序查询Student表中的全部记录*/
SELECT class,YEAR(NOW())-YEAR(sbirthday) AS age FROM student ORDER BY class ASC,age ASC
/*查询“男”教师及其所上的课程*/
SELECT tname,cname FROM course JOIN teacher ON course.`tno`=teacher.`tno` WHERE teacher.`tsex`='男'
/*查询最高分同学的Sno、Cno和Degree列*/
SELECT student.sno,cno,degree FROM score JOIN student ON score.`sno`=student.`sno`
WHERE degree=(
SELECT MAX(degree) FROM score
)
/*查询和“李军”同性别的所有同学的Sname*/
SELECT sname FROM student WHERE ssex=(
SELECT ssex FROM student WHERE sname='李军'
)
/*查询和“李军”同性别并同班的同学Sname*/
SELECT sname FROM student WHERE ssex=(SELECT ssex FROM student WHERE sname='李军') AND class=(SELECT class FROM student WHERE sname='李军')
/*查询所有选修“计算机导论”课程的“男”同学的成绩表*/
SELECT * FROM score JOIN student ON score.`sno`=student.`sno` JOIN course ON score.`cno`=course.`cno`
CREATE TABLE product_type(
protype_id INT PRIMARY KEY,
protype_name VARCHAR(20)
)
DESC product_type;
CREATE TABLE product(
pro_id INT PRIMARY KEY,
pro_name VARCHAR(50),
protype_id INT,
price INT,
pinpai VARCHAR(5),
chandi VARCHAR(5),
CONSTRAINT product_product_type_fk
FOREIGN KEY(protype_id) REFERENCES
product_type(protype_id)
)
DESC product;
INSERT INTO product_type VALUES(1,'家用电器');
INSERT INTO product_type VALUES(2,'手机数码');
INSERT INTO product_type VALUES(3,'电脑办公');
INSERT INTO product_type VALUES(4,'图书影像');
INSERT INTO product_type VALUES(5,'家居家具');
INSERT INTO product_type VALUES(6,'服装配饰');
INSERT INTO product_type VALUES(7,'个护化妆');
INSERT INTO product_type VALUES(8,'运动户外');
INSERT INTO product_type VALUES(9,'汽车用品');
INSERT INTO product_type VALUES(10,'食品酒水');
INSERT INTO product_type VALUES(11,'营养保健');
SELECT * FROM product_type;
INSERT INTO product VALUES(1,'康佳(KONKA)42英寸全高清液晶电视',1,1999,'康佳','深圳');
SELECT * FROM product;
INSERT INTO product VALUES(2,'索尼(SONY)4G手机(黑色)',2,3288,'索尼','深圳');
INSERT INTO product VALUES(3,'海信(Hisense)55英寸智能电视',1,4199,'海信','青岛');
INSERT INTO product VALUES(4,'联想(Lenovo)14.0英寸笔记本电脑',3,5499,'联想','北京');
INSERT INTO product VALUES(5,'索尼(SONY)13.3英寸触控超极本',3,11499,'索尼','天津');
INSERT INTO product VALUES(11,'索尼(SONY)60英寸全高清液晶电视',1,6999,'索尼','天津');
INSERT INTO product VALUES(12,'联想(Lenovo)14.0英寸笔记本电脑',3,2999,'联想','北京');
INSERT INTO product VALUES(13,'联想 双卡双待3G手机',2,988,'联想','北京');
INSERT INTO product VALUES(15,'惠普(HP)黑白激光打印机',3,1169,'惠普','天津');
/*查询价格在1000-5000之间品牌为联想的商品名称、商品价格、产品类型*/
SELECT pro_name,price,protype_name FROM product JOIN product_type ON product.`protype_id`=product_type.`protype_id`
WHERE (price BETWEEN 1000 AND 5000) AND (pro_name LIKE '%联想%');
/*查询ID为5的商品的产品类型相同的所有品牌的品牌、产地、此品牌的商品数量*/
SELECT * FROM product JOIN product_type ON product.`protype_id`=product_type.`protype_id`
WHERE protype_name=(SELECT protype_name FROM product JOIN product_type ON product.`protype_id`=product_type.`protype_id`
WHERE pro_id=5)
/*删除产品类型表中ID大于7的记录*/
DELETE FROM product_type WHERE protype_id>7;
/*修改'家居家具'为'家具用品'*/
UPDATE product_type SET protype_name='家具用品' WHERE protype_id=5;
/*查询‘家用电器’下所有商品的品牌和价格*/
SELECT pinpai,price FROM product JOIN product_type ON product.`protype_id`=product_type.`protype_id`
WHERE protype_name='家用电器';
CREATE TABLE student(
sno VARCHAR(20) PRIMARY KEY,
sname VARCHAR(20) NOT NULL,
ssex VARCHAR(20) NOT NULL,
sbirthday DATETIME,
class VARCHAR(20)
)
DESC student;
CREATE TABLE teacher(
tno VARCHAR(20) PRIMARY KEY,
tname VARCHAR(20) NOT NULL,
tsex VARCHAR(20) NOT NULL,
tbirthday DATETIME,
prof VARCHAR(20),
depart VARCHAR(20) NOT NULL
)
DESC teacher;
CREATE TABLE course(
cno VARCHAR(20) PRIMARY KEY,
cname VARCHAR(20) NOT NULL,
tno VARCHAR(20) NOT NULL,
CONSTRAINT course_teacher_fk
FOREIGN KEY(tno) REFERENCES
teacher(tno)
)
DESC course;
CREATE TABLE score(
sno VARCHAR(20) NOT NULL,
cno VARCHAR(20) NOT NULL,
degree DECIMAL(4,1),
CONSTRAINT score_student_fk
FOREIGN KEY(sno) REFERENCES
student(sno),
CONSTRAINT score_course_fk
FOREIGN KEY(cno) REFERENCES
course(cno)
)
DESC score;
INSERT INTO student VALUES('108','曾华','男',19770901,'95033');
SELECT * FROM student;
INSERT INTO student VALUES('105','匡明','男',19751002,'95031');
INSERT INTO student VALUES('107','王丽','女',19760123,'95033');
INSERT INTO student VALUES('101','李军','男',19760220,'95033');
INSERT INTO student VALUES('109','王芳','女',19750210,'95031');
INSERT INTO student VALUES('103','陆君','男',19740603,'95031');
INSERT INTO teacher VALUES('804','李诚','男',19581202,'副教授','计算机系');
SELECT * FROM teacher;
INSERT INTO teacher VALUES('856','张旭','男',19690312,'讲师','电子工程系');
INSERT INTO teacher VALUES('825','王萍','女',19720505,'助教','计算机系');
INSERT INTO teacher VALUES('831','刘冰','女',19770814,'助教','电子工程系');
INSERT INTO course VALUES('3-105','计算机导论','825');
SELECT * FROM course;
INSERT INTO course VALUES('3-245','操作系统','804');
INSERT INTO course VALUES('6-166','数字电路','856');
INSERT INTO course VALUES('9-888','高等数学','831');
INSERT INTO score VALUES('103','3-245',86);
SELECT * FROM score;
INSERT INTO score VALUES('105','3-245',75);
INSERT INTO score VALUES('109','3-245',68);
INSERT INTO score VALUES('103','3-105',92);
INSERT INTO score VALUES('105','3-105',88);
INSERT INTO score VALUES('109','3-105',76);
INSERT INTO score VALUES('101','3-105',64);
INSERT INTO score VALUES('107','3-105',91);
INSERT INTO score VALUES('108','3-105',78);
INSERT INTO score VALUES('101','6-166',85);
INSERT INTO score VALUES('107','6-166',79);
INSERT INTO score VALUES('108','6-166',81);
TRUNCATE TABLE score;
/*查询Student表中的所有记录的Sname、Ssex和Class列*/
SELECT sname,ssex,class FROM student;
/*查询教师所有的单位即不重复的Depart列*/
SELECT DISTINCT depart FROM teacher;
/*查询Student表的所有记录*/
SELECT * FROM student;
/*查询Score表中成绩在60到80之间的所有记录*/
SELECT * FROM score WHERE degree BETWEEN 60 AND 80;
/*查询Score表中成绩为85，86或88的记录*/
SELECT * FROM score WHERE degree=85 OR degree=86 OR degree=88;
/*查询Student表中“95031”班或性别为“女”的同学记录*/
SELECT * FROM student WHERE class='95031' OR ssex='女';
/*以Class降序查询Student表的所有记录*/
SELECT * FROM student ORDER BY class DESC;
/*以Cno升序、Degree降序查询Score表的所有记录*/
SELECT * FROM score ORDER BY cno ASC,degree DESC;
/*查询“95031”班的学生人数*/
SELECT class,COUNT(class) FROM student GROUP BY class;
/*查询Score表中的最高分的学生学号和课程号*/
SELECT student.sno,cno FROM score JOIN student ON score.`sno`=student.`sno`
WHERE degree=(
SELECT MAX(degree) FROM score JOIN student
)
