1.识别实体

实体：职员
属性：编号、姓名、性别、部门、权限

实体：打卡机
属性：编号、位置

实体关系：打卡
属性：流水号、打卡日期、打卡时间、职员编号、打卡机编号

2.E-R图

image.png

3.数据表图

1图1.png

4.数据库图

职员表

![ 捕获222.PNG
打卡机表 捕获333.PNG

数据库表

9999999获.PNG

5登录注册界面

捕获1.PNG

点击“登录”按钮则登录系统

   private void bt_Login_Click(object sender, EventArgs e)
        {
            String connStr = ConfigurationManager.ConnectionStrings["Attendance"].ConnectionString;
            SqlConnection sqlConn = new SqlConnection(connStr);
            try
            {
                // 连接数据库
                sqlConn.Open();

                // 构造命令发送给数据库
                String sqlStr = "select * from EMPLOYEE where ID=@id and PASSWORD=@pwd";
                SqlCommand cmd = new SqlCommand(sqlStr, sqlConn);

                // 注意是用用户ID登录，而不是用户名，用户名可能会重复
                cmd.Parameters.Add(new SqlParameter("@id", this.tb_User.Text.Trim()));
                cmd.Parameters.Add(new SqlParameter("@pwd", this.tb_Password.Text.Trim()));

                SqlDataReader dr = cmd.ExecuteReader();

                // 如果从数据库中查询到记录，则表示可以登录
                if (dr.HasRows)
                {
                    dr.Read();
                    UserInfo.userId = int.Parse(dr["ID"].ToString());
                    UserInfo.userName = dr["NAME"].ToString();
                    UserInfo.userPwd = dr["PASSWORD"].ToString();
                    UserInfo.userRole = dr["ROLE"].ToString();
                    UserInfo.userDepartment = dr["DEPARTMENT"].ToString();
                    UserInfo.userGender = dr["GENDER"].ToString();

                    MessageBox.Show(UserInfo.userRole + "登录成功");

                    if (UserInfo.userRole == "职员")
                    {
                        Form3 Form = new Form3();
                        Form.Show();
                        //// 显示收银员主界面
                        //MainFormUser formUser = new MainFormUser();
                        //formUser.Show();

                        //// 隐藏登录界面
                        this.Hide();
                    }

                    if (UserInfo.userRole == "管理员")
                    {
                        Form4 Form = new Form4();
                        Form.Show();
                        //// 显示库管员主界面
                        //MainFormAdmin formAdmin = new MainFormAdmin();
                        //formAdmin.Show();

                        //// 隐藏登录界面
                        this.Hide();
                    }
                }
                else
                {
                    MessageBox.Show("用户名或密码错误", "提示", MessageBoxButtons.OK, MessageBoxIcon.Error);
                }
            }
            catch (Exception exp)
            {
                MessageBox.Show("访问数据库错误：" + exp.Message);
            }
            finally
            {
                sqlConn.Close();
            }
        }

        // 点击“退出”按钮则退出应用程序

捕获2.PNG
捕获3.PNG

点击录入职员按钮进入Form2

Form2 Form = new Form2();
          Form.Show();

捕获4.PNG

点击注册按钮注册

 String id = this.textBox1.Text.Trim();
            String name = this.textBox2.Text.Trim();
            String password = this.textBox3.Text.Trim();
            String gender = this.comboBox1.Text.ToString();
            String department = this.comboBox2.Text.ToString();
            String role = this.comboBox3.Text.ToString();

            // 连接字符串，注意与实际环境保持一致
            String connStr = ConfigurationManager.ConnectionStrings["Attendance"].ConnectionString;
            SqlConnection sqlConn = new SqlConnection(connStr);
            try
            {
                // 连接数据库
                sqlConn.Open();
                

                // 构造命令
                String sqlStr = "insert into employee(ID, NAME, GENDER, DEPARTMENT, ROLE, PASSWORD) values(@id, @name, @gender, @department, @role, @password)";
                SqlCommand cmd = new SqlCommand(sqlStr, sqlConn);
                String sqlSt = "select MAX(id+1) as id from employee";

                // SQL字符串参数赋值
                cmd.Parameters.Add(new SqlParameter("@id", id));
                cmd.Parameters.Add(new SqlParameter("@name", name));
                cmd.Parameters.Add(new SqlParameter("@gender", gender));
                cmd.Parameters.Add(new SqlParameter("@department", department));
                cmd.Parameters.Add(new SqlParameter("@role", role));
                cmd.Parameters.Add(new SqlParameter("@password", password));

                // 将命令发送给数据库
                int res = cmd.ExecuteNonQuery();

                // 根据返回值判断是否插入成功
                if (res != 0)
                {
                    MessageBox.Show("职员信息录入成功");
                }
                else
                {
                    MessageBox.Show("职员信息录入失败");
                }
            }
            catch (Exception exp)
            {
                MessageBox.Show("访问数据库错误：" + exp.Message);
            }
            finally
            {
                sqlConn.Close();
            }
        }

        private void Form2_Load(object sender, EventArgs e)
        {

        }

6职员打卡

捕获9.PNG

点击打开串口按钮

 // 串口已打开，此时需要关闭
            if (serialPort1.IsOpen)
            {
                serialPort1.Close();
                this.toolStripStatusLabel1.Text = "已关闭串口" + serialPort1.PortName.ToString();
                buttonOpenCOM.Text = "打开";
                return;
            }
            // 否则打开串口
            else
            {
                serialPort1.PortName = comboBoxCOMList.Text;
                InitSerialPort();

                try
                {
                    serialPort1.Open();
                    this.toolStripStatusLabel1.Text = "已打开串口" + serialPort1.PortName.ToString();
                    buttonOpenCOM.Text = "关闭";
                }
                catch (Exception ex)
                {
                    this.toolStripStatusLabel1.Text = "打开串口失败，原因：" + ex.Message;
                    return;
                }
            }