数据库设计

1.识别实体

①打卡机
②员工

2.E-R图

E-R图.jpg

3.数据表

员工
PK	工号
	姓名
	年龄
	职位
	部门

打卡机
PK	编号
	位置

合并后生成的新表：

打卡
PK	ID
FK1	工号
	日期
FK2	编号
	时间

4.数据库表

CREATE TABLE [dbo].[dakaji](
    [number] [varchar](50) NOT NULL,
    [location] [varchar](50) NULL,
 CONSTRAINT [PK_Table_1] PRIMARY KEY CLUSTERED 
(
    [number] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]

CREATE TABLE [dbo].[daka information](
    [ID] [varchar](50) NOT NULL,
    [job number] [varchar](50) NULL,
    [date] [varchar](50) NULL,
    [number] [varchar](50) NULL,
    [time] [time](7) NULL,
 CONSTRAINT [PK_Table_2] PRIMARY KEY CLUSTERED 
(
    [ID] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]

CREATE TABLE [dbo].[employer](
    [job number] [nchar](10) NOT NULL,
    [name] [nchar](10) NULL,
    [age] [nchar](10) NULL,
    [position] [nchar](10) NULL,
    [department] [nchar](10) NULL,
 CONSTRAINT [PK_Table_3] PRIMARY KEY CLUSTERED 
(
    [job number] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]