Initial commit

实验一.txt

+# 本代码使用 MariaDB
+
+create database studentdb;
+use studentdb;
+
+create table employee (
+emp_no char(5) not null comment "员工编号", 
+emp_name char(10) not null comment "员工姓名", 
+emp_sex char(1) not null comment "性别", 
+emp_dept char(4) not null comment "所属部门", 
+emp_title char(6) not null comment "职称", 
+emp_date_hired datetime not null comment "到职日", 
+emp_birthday datetime not null comment "生日",
+emp_salary char(5) not null comment "薪水", 
+emp_addr varchar(60) not null comment "住址", 
+emp_mod_date datetime not null DEFAULT CURRENT_TIMESTAMP comment "操作时间", 
+PRIMARY KEY (emp_no)
+);
+# 查看所有表可以用 show full columns from employee;
+# 或者用 desc employee; 嘛
+
+# 更改表名可以用 ALTER TABLE test RENAME TO test2;
+create table customer (
+cust_id char(5) not null comment "客户号", 
+cust_name char(20) not null comment "客户名称", 
+addr char(40) not null comment "客户住址", 
+tel_no char(10) not null comment "客户电话", 
+zip char(6) not null comment "邮政编码",
+PRIMARY KEY (cust_id)
+);
+
+create table sale_item (
+order_no int not null comment "订单编号", 
+prod_id char(5) not null comment "产品编号", 
+qty int not null comment "销售数量", 
+unit_price numeric(9, 2) not null comment "单价",
+order_date datetime not null comment "订单日期",
+PRIMARY KEY (order_no, prod_id)
+);
+
+create table product (
+prod_id char(5) not null comment "产品编号", 
+prod_name char(20) not null comment "产品名称", 
+PRIMARY KEY (prod_id)
+);
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实验二.md

+# 实验二
+
+## 我们预想的表结构
+
+### 员工人事表
+
+| 员工编号 | 员工姓名 | 性别 | 所属部门 | 职称 | 到职日 | 生日 | 薪水 | 住址 |
+| : --- | --- | --- | --- | --- | --- | --- | --- | ---: |
+| 10000 | 马化腾 | 男 | 董事会 | 总经理 | 2016-10-01 09:00:00 | 1998-07-11 12:00:00 | 25111 | 中华人民共和国北京市西城区西长安街街道 |
+| 10001 | 刘强东 | 男 | 董事会 | 副经理 | 2016-10-01 09:00:00 | 1974-12-16 15:00:00 | 20000 | 深圳市龙华区民治街道梅龙路2号星河盛世 |
+| 10002 | 董明珠 | 女 | 财务部 | 会计 | 2016-10-01 09:00:00 | 1954-08-01 17:00:00 | 5251 | 广州市越秀区培正路2号 |
+
+#### 示例代码
+
+```mysql
+INSERT INTO employee (
+    emp_no, emp_name, emp_sex, emp_dept, emp_title, emp_date_hired, emp_birthday, emp_salary, emp_addr, emp_mod_date
+) VALUE (
+    "10000", "马化腾", "男", "董事会", "总经理", "2016-10-01 09:00:00", "1998-07-11 12:00:00", "25111", "中华人民共和国北京市西城区西长安街街道", NOW()
+), (
+    "10001", "刘强东", "男", "董事会", "副经理", "2016-10-01 09:00:00", "1974-12-16 15:00:00", "20000", "深圳市龙华区民治街道梅龙路2号星河盛世", NOW()
+), (
+    "10002", "董明珠", "女", "财务部", "会计", "2016-10-01 09:00:00", "1954-08-01 17:00:00", "5251", "广州市越秀区培正路2号", NOW()
+);
+```
+
+如果更改某一条可以用
+
+```mysql
+UPDATE employee SET emp_mod_date=NOW() where emp_no="10000";
+```
+
+删除某一条可以用
+
+```mysql
+DELETE FROM employee WHERE emp_no="10000";
+# delete from deleteRowDemo where StudentName='' OR StudentName IS NULL;
+```
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[Kiryuu Sakuya]

讲真，我当时写这个 markdown 的时候居然没有看出来……