更新了数据库部分的文档和代码

Day36-40/code/HRS_create_and_init.sql

@@ -51,15 +51,15 @@ insert into tb_emp values
 	(3588, '朱九真', '会计', 5566, 2500, null, 10);
 
 
--- 查询薪资最高的员工姓名和工资
+-- 查询月薪最高的员工姓名和工资
 
--- 查询员工的姓名和年薪((月薪+补贴)*12)
+-- 查询员工的姓名和年薪((月薪+补贴)*13)
 
 -- 查询有员工的部门的编号和人数
 
 -- 查询所有部门的名称和人数
 
--- 查询薪资最高的员工(Boss除外)的姓名和工资
+-- 查询月薪最高的员工(Boss除外)的姓名和工资
 
 -- 查询薪水超过平均薪水的员工的姓名和工资
 
@@ -69,24 +69,4 @@ insert into tb_emp values
 
 -- 查询主管的姓名和职位
 
--- 查询薪资排名4~6名的员工姓名和工资
-
--- use hrs;
-
--- drop procedure if exists sp_avg_sal_by_dept;
-
-
--- create procedure sp_avg_sal_by_dept(dno integer, out avg_sal float)
--- begin 
---     select avg(sal) into avg_sal from tb_emp where dno=dno;
--- end;
-
-
-
-
--- call sp_avg_sal_by_dept(10, @avgSal);
-
--- select @avgSal;
-
-
-
+-- 查询月薪排名4~6名的员工姓名和工资

Day36-40/code/bank_create_and_init.sql

-drop database if exists bank;
-
-create database bank default charset utf8;
-
-use bank;
-
-create table tb_account
-(
-accid char(8) primary key,
-accowner varchar(20) not null,
-accbalance float not null default 0
-);
-
-insert into tb_account values (11223344, '王大锤', 1000);
-insert into tb_account values (22334455, '李小龙', 1000);
\ No newline at end of file

Day36-40/code/booksys_create_and_init.sql

-drop database if exists booksys;
-
-create database booksys default charset utf8;
-
-use booksys;
-
-create table tb_book
-(
-bookid integer not null,
-isbn char(13) not null,
-bname varchar(100) not null,
-price decimal(8,2) not null,
-author varchar(100) not null,
-publisher varchar(50) not null,
-pubdate date,
-intro varchar(500),
-lended bit default 0,
-counter integer default 0,
-primary key (bookid)
-);
-
-create table tb_reader
-(
-readerid integer not null,
-rname varchar(20) not null,
-gender bit not null,
-tel char(11) not null,
-birth date,
-regdate date not null,
-available bit default 1,
-primary key (readerid)
-);
-
-create table tb_record
-(
-recordid integer not null auto_increment,
-bid integer not null,
-rid integer not null,
-lenddate datetime not null,
-backdate datetime,
-pulishment decimal(6,2),
-primary key (recordid)
-);
-
-alter table tb_record add constraint fk_record_bid foreign key (bid) references tb_book (bookid) on update cascade;
-alter table tb_record add constraint fk_record_rid foreign key (rid) references tb_reader (readerid) on update cascade;
\ No newline at end of file

Day36-40/关系型数据库MySQL.md

@@ -350,16 +350,14 @@
    select stuname from tb_student where stuaddr is not null;
    
    -- 查询学生选课的所有日期(去重)
-   select distinct scdate from tb_score;
+   select distinct seldate from tb_record;
    
    -- 查询学生的家庭住址(去重)
    select distinct stuaddr from tb_student where stuaddr is not null;
    
    -- 查询男学生的姓名和生日按年龄从大到小排列(排序)
-   -- asc (ascending) - 升序（从小到大）/ desc (descending) - 降序（从大到小）
-   select stuname as 姓名, year(now())-year(stubirth) as 年龄 from tb_student where stusex=1 order by 年龄 desc;
+   select stuname as 姓名, datediff(curdate(), stubirth) div 365 as 年龄 from tb_student where stusex=1 order by 年龄 desc;
    
-   -- 聚合函数：max / min / count / sum / avg
    -- 查询年龄最大的学生的出生日期(聚合函数)
    select min(stubirth) from tb_student;
    
@@ -370,51 +368,42 @@
    select stusex, count(*) from tb_student group by stusex;
    
    -- 查询课程编号为1111的课程的平均成绩(筛选和聚合函数)
-   select avg(scmark) from tb_score where couid=1111;
+   select avg(score) from tb_record where cid=1111;
    
    -- 查询学号为1001的学生所有课程的平均分(筛选和聚合函数)
-   select avg(scmark) from tb_score where stuid=1001;
+   select avg(score) from tb_record where sid=1001;
    
    -- 查询每个学生的学号和平均成绩(分组和聚合函数)
-   select stuid as 学号, avg(scmark) as 平均分 from tb_score group by stuid;
+   select sid as 学号, avg(score) as 平均分 from tb_record group by sid;
    
    -- 查询平均成绩大于等于90分的学生的学号和平均成绩
    -- 分组以前的筛选使用where子句 / 分组以后的筛选使用having子句
-   select stuid as 学号, avg(scmark) as 平均分 from tb_score group by stuid having 平均分>=90;
+   select sid as 学号, avg(score) as 平均分 from tb_record group by sid having 平均分>=90;
    
    -- 查询年龄最大的学生的姓名(子查询/嵌套的查询)
-   select stuname from tb_student where stubirth=(
-   	select min(stubirth) from tb_student
-   );
+   select stuname from tb_student where stubirth=( select min(stubirth) from tb_student );
    
    -- 查询年龄最大的学生姓名和年龄(子查询+运算)
-   select stuname as 姓名, year(now())-year(stubirth) as 年龄 from tb_student where stubirth=(
-   	select min(stubirth) from tb_student
-   );
+   select stuname as 姓名, datediff(curdate(), stubirth) div 365 as 年龄 from tb_student where stubirth=( select min(stubirth) from tb_student );
    
    -- 查询选了两门以上的课程的学生姓名(子查询/分组条件/集合运算)
-   select stuname from tb_student where stuid in (
-   	select stuid from tb_score group by stuid having count(stuid)>2
-   )
+   select stuname from tb_student where stuid in ( select stuid from tb_record group by stuid having count(stuid)>2 );
    
    -- 查询学生姓名、课程名称以及成绩(连接查询)
-   select stuname, couname, scmark from tb_student t1, tb_course t2, tb_score t3 where t1.stuid=t3.stuid and t2.couid=t3.couid and scmark is not null;
+   select stuname, couname, score from tb_student t1, tb_course t2, tb_record t3 where stuid=sid and couid=cid and score is not null;
    
    -- 查询学生姓名、课程名称以及成绩按成绩从高到低查询第11-15条记录(内连接+分页)
-   select stuname, couname, scmark from tb_student t1 inner join tb_score t3 on t1.stuid=t3.stuid inner join tb_course t2 on t2.couid=t3.couid where scmark is not null order by scmark desc limit 5 offset 10;
+   select stuname, couname, score from tb_student inner join tb_record on stuid=sid inner join tb_course on couid=cid where score is not null order by score desc limit 5 offset 10;
    
-   select stuname, couname, scmark from tb_student t1 inner join tb_score t3 on t1.stuid=t3.stuid inner join tb_course t2 on t2.couid=t3.couid where scmark is not null order by scmark desc limit 10, 5;
+   select stuname, couname, score from tb_student inner join tb_record on stuid=sid inner join tb_course on couid=cid where score is not null order by score desc limit 10, 5;
    
    -- 查询选课学生的姓名和平均成绩(子查询和连接查询)
-   select stuname, avgmark from tb_student t1, (select stuid, avg(scmark) as avgmark from tb_score group by stuid) t2 where t1.stuid=t2.stuid;
+   select stuname, avgmark from tb_student, ( select sid, avg(score) as avgmark from tb_record group by sid ) temp where stuid=sid;
    
-   select stuname, avgmark from tb_student t1 inner join 
-   (select stuid, avg(scmark) as avgmark from tb_score group by stuid) t2 on t1.stuid=t2.stuid;
+   select stuname, avgmark from tb_student inner join ( select sid, avg(score) as avgmark from tb_record group by sid ) temp on stuid=sid;
    
-   -- 内连接（inner join）- 只有满足连接条件的记录才会被查出来
-   -- 外连接（outer join）- 左外连接(left outer join) / 右外连接(right outer join) / 全外连接
    -- 查询每个学生的姓名和选课数量(左外连接和子查询)
-   select stuname, ifnull(total, 0) from tb_student t1 left outer join (select stuid, count(stuid) as total from tb_score group by stuid) t2 on t1.stuid=t2.stuid;
+   select stuname, ifnull(total, 0) from tb_student left outer join ( select sid, count(sid) as total from tb_record group by sid ) temp on stuid=sid;
    ```
 
 4. DCL

Day41-55/07.日志和调试.md

 ## 日志和调试
 
-
-
+在项目开发阶段，显示足够的调试信息以辅助开发人员调试代码还是非常必要的.