diff --git "a/08 \350\256\270\350\215\243\346\263\225/20230306 \345\255\220\346\237\245\350\257\242.MD" "b/08 \350\256\270\350\215\243\346\263\225/20230306 \345\255\220\346\237\245\350\257\242.MD" new file mode 100644 index 0000000000000000000000000000000000000000..362fb9795f7d720174a207ed1fe7de4cb84ad0c5 --- /dev/null +++ "b/08 \350\256\270\350\215\243\346\263\225/20230306 \345\255\220\346\237\245\350\257\242.MD" @@ -0,0 +1,84 @@ +# 笔记 + +```mysql +IN 在指定的集合范围内，多选一 +NOT IN 不在指定的集合范围内 +ANY 子查询返回列表中，有任意一个满足即可 +SOME 与ANY等同，使用SOME的地方都可以使用ANY +ALL 子查询返回列表的所有值都必须满足 +``` + +# 作业 + +```mysql +create database otto charset utf8; +use otto; +create table stuinfo( +stuNO varchar(10), +stName varchar(10), +stuSex varchar(4), +stuAge int, +stuAddress varchar(10), +stSeat int +); +create table stuExam( +examNo int, +stuNo varchar(10), +writtenExam int, +labExam int +); +create table stuMarks( +examNo int, +stuID varchar(10), +score INT +); +insert into stuinfo values ("s2501","张秋利","男",20,"美国硅谷",1),("s2502","李斯文","女",18,"湖北武汉",2),("s2503","马文才","男",18,"湖南长沙",3),("s2504","欧阳俊雄","女",21,"湖北武汉",4),("s2505","梅超风","男",20,"湖北武汉",5),("s2506","陈旋风","男",19,"美国硅谷",6); +insert into stuExam values (1,"s2501",50,70),(2,"s2502",60,65),(3,"s2503",86,70),(4,"s2504",40,80),(5,"s2505",70,85),(6,"s2506",85,90); +insert into stuMarks values (1,"s2501",88),(2,"s2501",92),(3,"s2501",53),(4,"s2502",60),(5,"s2502",99),(6,"s2503",82); +-- 在如图的数据表上完成以下题目 +-- +-- 1.查询出年龄比班上平均年龄大的学生的信息 +select * from stuinfo where stuAge > (select avg(stuAge)from stuinfo); +-- 2.查询出每个学生的学号，姓名，性别和选修课程的最高分（stuMarks） +select stuNO,stName,stuSex,max(stuMarks.score) from stuinfo left JOIN stuMarks on stuinfo.stuNO=stuMarks.stuID GROUP BY stuNO; +-- 3.查询出每个学生的学号，姓名，性别和考试平均分（stuExam） +select stuinfo.stuNO,stName,stuSex,(stuExam.writtenExam+stuExam.labExam)/2 from stuinfo left join stuExam on stuinfo.stuNO=stuexam.stuNo GROUP BY stName; +-- 4.查询性别是男并且年龄大于等于20的学生的信息(用两种方法实现：普通查询和子查询) +select * from stuinfo where stuSex = "男" and stuAge >= 20; +select * from stuinfo where stuNO in(select stuNO from stuinfo where stuSex = "男" and stuAge >= 20); +-- +-- 5.查询出年龄比所有男生年龄都大的女生的信息 +select * from stuinfo where stuSex = "女" and stuAge > (select max(stuAge) from stuinfo where stuSex = "男"); +-- +-- 6.查询出所有选修课程都及格的学生的信息 （stuMarks） +select * from stuinfo inner join stuMarks on stuinfo.stuNO = stuMarks.stuID where score >= 60 ; +-- +-- 7.查询出参加考试的学生的信息（用表连接，in二种方法做）（stuMarks） +select * from stuinfo right join stuMarks on stuinfo.stuNO = stuMarks.stuID GROUP BY stName; +select * from stuinfo where stuNO in(select stuID from stuMarks); +-- +-- 8.查询出没有参加考试的学生的信息（用表连接，in二种方法做）（stuMarks） +select * from stuinfo left join stuMarks on stuinfo.stuNO = stuMarks.stuID where score is null; +select * from stuinfo where stuNO not in(select stuID from stuMarks); +-- +-- 9.将有一门成绩成绩大于90分的学生的基本信息查询出来（stuMarks） +select * from stuinfo inner join stuMarks on stuinfo.stuNO = stuMarks.stuID where score >= 90; +-- +-- 10.查询出平均成绩在80分以上的学生的基本信息（stuMarks） +select * from stuinfo left join stuMarks on stuinfo.stuNO = stuMarks.stuID GROUP BY stuNO HAVING score >= (select avg(score)from stuMarks); +-- +-- 11.查询出某同学所有考试成绩比“张秋利”同学所有分数都高的学生基本信息（stuMarks） +select stuinfo.* from stuMarks right join stuinfo on stuinfo.stuNo=stuMarks.stuid where score>(select max(score) from stumarks where stuid='s2501'); +-- +-- 12.查询出某同学所有考试成绩只需要比“张秋利”同学某个分数高的学生基本信息（stuMarks） +select stuinfo.* from stuinfo left join stuExam on stuinfo.stuNO = stuExam.stuNO +where writtenExam>(select writtenExam from stuExam where stuNo=(select stuNo from stuinfo where stuname='张秋利')) OR labExam>(select labExam from stuExam where stuNo=(select stuNo from stuinfo where stuname='张秋利')); +-- +-- 13.查询班上比所有男生年龄都要大的女生的信息 +select * from stuinfo where stuAge>(select max(stuAge) from stuinfo where stuSex='男') and stuSex='女'; +-- +-- 14.查询出只是比某个男生年龄大的女生的信息 +select * from stuinfo where stuAge>any(select stuAge from stuinfo where stuSex='男') and stusex='女'; +-- +``` + diff --git "a/08 \350\256\270\350\215\243\346\263\225/20230308 \345\244\247\344\275\234\344\270\232.md" "b/08 \350\256\270\350\215\243\346\263\225/20230308 \345\244\247\344\275\234\344\270\232.md" new file mode 100644 index 0000000000000000000000000000000000000000..70e241490b9d07c4846dace87d7b77b407e7c939 --- /dev/null +++ "b/08 \350\256\270\350\215\243\346\263\225/20230308 \345\244\247\344\275\234\344\270\232.md" @@ -0,0 +1,104 @@ +# 笔记 + +```mysql +alter table A modify B C 修改字段类型 +alter table A drop / add B C 删除/添加字段 +update A set B = ? where 修改字段内容 +default 默认值 +delete from 表名称 where 条件 删除字段内容 +like "%_" 两符号需与 like 联用 +(not) between 1 and 3; 数字区间 +(not) in ('', '', ''); 字符区间 +order by B asc / desc 升降排序 +``` + +# 作业 + +```mysql +-- 1. 根据前面提供的表结构和表数据，创建数据库并分别创建这张四张表；并插入相关数据。(提醒：外键请注意建表顺序和插入数据的顺序) （30分） +create database xiaoshuo charset utf8; +use xiaoshuo; + + +create table vip( +vip_id varchar(20) primary key comment "等级编号", +vip_name varchar(20) comment "等级名称" +); +create table type ( +type_id varchar(20) primary key comment "类型编号", +type_name varchar(20) not null unique key comment "类型名称" +); +create table author ( +author_id int primary key comment "作家编号", +author_name varchar(20) not null unique key comment "作家姓名", +credits int comment "积分", +vip_id varchar(20) not null comment "等级编号", +foreign key(vip_id) references vip(vip_id) +); +create table story( +story_id int primary key auto_increment comment "作品编号", +author_id int comment "作家编号", +type_id varchar(20) comment "类型编号", +story_name varchar(50) comment "作品名称", +views_number int comment "浏览量", +foreign key(author_id) references author(author_id), +foreign key(type_id) references type(type_id) +); + + + +insert into vip values("VIP1","青铜作家"),("VIP2","白银作家"),("VIP3","黄金作家"),("VIP4","钻石作家"); +insert into type values("L01","玄幻"),("L02","奇幻"),("L03","武侠"),("L04","仙侠"),("L05","都市"); +insert into author values(1001,"朱逸群",600,"VIP01"),(1002,"范建",8510,"VIP04"),(1003,"史珍香",981,"VIP02"),(1004,"范统",2364,"VIP02"),(1005,"杜子腾",257,"VIP01"),(1006,"刘产",678,"VIP02"),(1007,"杜琦燕",438,"VIP03"); +insert into story values(1,1002,"L03","母猪产后与护理师的二三事",6541), +(2,1005,"L04","拖拉机大战蜘蛛侠",563), +(3,1003,"L01","这只小龙虾不正经",8754), +(4,1006,"L04","一个爹爹三个娃",36354), +(5,1006,"L01","皇上滚开本宫只劫财",3674), +(6,1005,"L05","给长城贴瓷砖在小太监",6541), +(7,1003,"L03","不科学御兽",1257), +(8,1005,"L01","镜面管理局",3216), +(9,1004,"L02","关于我成为灭魂师之后",1147), +(10,1004,"L05","公子别秀",2078); + + +-- 2. 将story 表中的story_name字段类型改成varchar(40) 。（2分） +alter table story modify story_name varchar(40); +desc story; +-- 3. 在author表中增加一个性别字段 字段名：author_sex,类型： char(10)，要求默认值为'男'。 （3分） +alter table author add author_sex char(10) default "男"; +-- 4. 将作家编号为1005、1007的作家性别改为'女' 。（2分） +update author set author_sex = "女" where author_id = 1005 or author_id = 1007; +-- 5. 作家杜子腾，写了一篇名为《拜登夸我很帅》的都市小说，有854个浏览量，请将这条信息插入到story表。（3分） +insert into story values(11,1005,"L05","拜登夸我很帅",854); +-- 6. 《拖拉机大战蜘蛛侠》这篇小说，浏览量涨了100，请更新story表中的相关数据。（2分） +update story set views_number = views_number + 100 where story_name = "拖拉机大战蜘蛛侠"; +-- 7. 请删除story表的中《皇上滚开本宫只劫财》这篇小说相关数据。（2分） +delete from story where story_name = "皇上滚开本宫只劫财"; +-- 8. 查询 浏览量大于 8000的小说的作者编号和小说作品名称。（2分） +select author_id,story_name from story where views_number > 8000; +-- 9. 查询积分大于1000 并且会员等级高于vip03的作家所有信息。（3分） +select * from author where credits > 1000 and vip_id>"VIP03"; +-- 10. 查询姓名以杜字开头的作家的姓名，积分和等级编号。（3分） +select author_name,credits,vip_id from author where author_name like "杜%"; +-- 11. 查询积分在100、1000之间的作家信息，以积分降序排列。 （3分） +select * from author where credits between 100 and 1000 order by credits desc; +-- 12. 查询出小说的总浏览量，最高浏览量，最小浏览量，平均浏览量，给字段用上中文别名。（3分） +select sum(views_number) 总浏览量,max(views_number) 最高浏览量,min(views_number) 最小浏览量,avg(views_number) 平均浏览量 from story; +-- 13. 查询各种等级的作家的平均积分和作家数量,并对查询结果使用中文别名。（3分） +select vip_id,avg(credits) 平均积分,count(vip_id) 作家数量 from author group by vip_id; +-- 14. 查询小说数量大于等于2的分类编号和小说数量。（4分） +select type_id,count(story_name) from story group by type_id having count(story_name) >= 2; +-- 15. 查询所有小说中浏览量最少的书的作品编号、作品名称和类型编号、浏览量。（4分） +select * from story where views_number = (select min(views_number) from story); +-- 16. 查询积分比刘产高的作者所有信息。（5分） +select * from author where credits > (select credits from author where author_name = "刘产"); +-- 17. 查询出哪些白银作家是没有写小说的，显示这些作家的姓名、等级名称。（8分） +select author_name,vip_name +from author inner join vip on author.vip_id = vip.vip_id +where author_id not in(select author_id from story); +-- 18. 找出写过作品浏览量大于5000的作家的所有作品中浏览量不到1000的作品信息（8分） +select * from story where views_number<1000 and author_id in (select author.author_id from author left join story on author.author_id = story.author_id where views_number >5000); +-- 19. 查询所有小说的小说编号、小说名称、浏览量、分类名称、作者姓名、作者积分、作者等级名称，结果字段要用中文别名，并按浏览量降序排列，如果浏览量一样的，再按积分降序排列。（10分) +select story_id 小说编号,story_name 小说名称,views_number 浏览量,type_id 分类名称,author.author_id 作者姓名,credits 作者积分,vip_id 作者等级 from story left join author on author.author_id = story.author_id ORDER BY views_number desc,credits desc; +```