3.13数据库单表练习题作业--宝安22期佘扬周
数据库单表练习题作业：#创建学生表
CREATE TABLE GRADE(
ID INT PRIMARY KEY AUTO_INCREMENT COMMENT'学号',
NAME VARCHAR(20) COMMENT'姓名',
AGE INT COMMENT'年龄',
CLASS INT COMMENT'班级',
CHINESE INT COMMENT'语文分数',
ENGLISH INT COMMENT'英语分数',
MATH INT COMMENT'数学分数'
)ENGINE=INNODB DEFAULT CHARSET=UTF8 COMMENT'学生表';
#插入表数据
insert into GRADE values
(1,'zhangsan',18,1832,80,90,77),
(2,'lisi',18,1832,90,90,90),
(3,'wangwu',19,1833,99,98,100),
(4,'zhaoliu',17,1833,85,78,85),
(5,'xiaoqi',17,1832,60,80,88),
(6,'xiaoba',18,1833,70,82,90);
1，查询1832班的成绩信息
select * from GRADE where CLASS=1832;
2，查询1833班，语文成绩大于80小于90的所有成绩信息
select * from GRADE where CLASS=1833 and CHINESE > 80 and CHINESE < 90;
3，查询学生表中5到10行的数据
select * from GRADE where ID in (5,6,7,8,9,10);
4，显示1832班英语成绩为98，数学成绩为77的姓名与学号,
select ID,NAME from GRADE where CLASS=1832 and ENGLISH=98 and MATH=77;
5，查询出1832班成绩并且按语文成绩排序（降序）
select * from GRADE where CLASS=1832 order by CHINESE desc;
6，查询1833班与1832班，语文成绩与数学成绩都小于80的姓名。
select NAME from GRADE where (CLASS=1832 or CLASS=1833) and (CHINESE<80 and MATH<80);
7，查询出没有参加语文考试的学生姓名和班级名称。
select NAME,CLASS from GRADE where CHINESE is null;
8，求出班上语文成绩不及格的学生姓名
select NAME from GRADE where CHINESE<60;
9，求出每个班的数学平均成绩
select CLASS,avg(MATH) from GRADE group by CLASS;
10、求出每个班级语文成绩总分 --涉及到每个的时候都需要分组
select CLASS,sum(CHINESE) from GRADE group by CLASS;
11、将语文成绩不及格的学生语文成绩改为60分
update GRADE set CHINESE=60 where CHINESE<60;
12、三科分数都大于70分的人名和年纪
select NAME,AGE from GRADE where CHINESE>70 and ENGLISH>70 and MATH>70;
13、求出英语分数高于70且其它任何一科目大于60分的人和班级
select NAME,CLASS from GRADE where ENGLISH>70 and (CHINESE>60 or MATH>60);
14、统计每个班的人数
select CLASS,count(NAME) from GRADE group by CLASS;
15、求每个班数学成绩大于80的人数
select CLASS,count(NAME) from GRADE where MATH>80 group by CLASS;
16、求出每个班英语成绩最高的分数和班级名称 --每个班英语成绩最高
select CLASS,max(ENGLISH) from GRADE group by CLASS;
17、给GRADE表增加3个字段（数据类型及长度自定义，建议要合理
alter table GRADE add(sex varchar(2),height float(3,2),phone bigint(11));
页:
[1]