c#实现增删查改操作

 

          CRUD 是指在做计算处理时的增加 (Create) 、查询 (Retrieve) （重新得到数据）、更新 (Update) 和删除 (Delete) 几个单词的首字母简写。主要被用在描述软件系统中数据库或者持久层的基本操作功能。

　　 In computing, CRUD is an acronym for create, retrieve, update, and delete. It is used to refer to the basic functions of a database or persistence layer in a software system.

　　 C reate new records

　　 R etrieve existing records

　　 U pdate existing records

D elete existing records.

在进入主界面后，点击员工设置；选择添加员工：

private void tsmiAdd_Click( object sender, EventArgs e)
                {
                         new FrmDealEmployee( "添加员工信息", null, this).ShowDialog();
                }

         为增强代码的重用性，添加员工与修改员工共用窗体信息，如果添加员工标签被激发，则该窗体的label显示： 添加员工信息 ；因为修改员工信息与新增功能相似，只介绍其中一个。

         实现新增员工的代码如下：

Employee emp = new Employee();
                                 if (txtEMPID.Text == "" || txtEmpName.Text == "" || txtMobilePhone.Text == "" ||
                                        txtPhone.Text == "" || txtEmpCertType.Text == "" ||
                                        txtEmpCertNum.Text == "" || txtDiscount.Text == "" ||
                                        txtAddress.Text == "")
                                {
                                        MessageBox.Show( "填写完整信息", "提示");
                                         return;
                                }
                                 float discount = 0.0f;
                                 try
                                {
                                         float.TryParse(txtDiscount.Text.Trim(), out discount);
                                }
                                 catch (Exception ee)
                                {
                                        MessageBox.Show( "折扣率错误", "提示");
                                         return;
                                }

                                emp.EmpID = NumberFormat.ConvertToFixLenString(txtEMPID.Text.Trim(), IDCode.EmployeeIDLength);
                                emp.Password = EnCriptPassword.MD5EnCriptPassword(emp.EmpID);
                                emp.UserRightCode = ""; //curemp.UserRightCode;权限
                                emp.EmpLevel = 0;

                                emp.RoleID = ( int)cmbRole.SelectedValue;
                                emp.DepartmentID = ( short)1; // cmbDepartment.SelectedValue;
                                emp.EmpCertNum = txtEmpCertNum.Text.Trim();
                                emp.EmpCertType = txtEmpCertType.Text.Trim();
                                emp.EmpDiscount = discount;
                                emp.EmpAddress = txtAddress.Text.Trim();
                                emp.EmpMobile = txtMobilePhone.Text.Trim();
                                emp.EmpName = txtEmpName.Text.Trim();
                                emp.EmpPhone = txtPhone.Text.Trim();
                                emp.UserBirthDate = dtpBirthDay.Value;



                                 if (EmployeeBLL.AddNewEmp(emp))
                                {
                                        MessageBox.Show( "修改成功", "提示");
                                         this.parent.RefreshEmpList(); //更新父窗体的信息
                                         this.Close();
                                }
                                 else
                                {
                                        MessageBox.Show( "修改失败", "提示");
                                }
                        }

            EmplyeeDAL.cs关于新增员工的功能如下：

public static bool AddNewEmp(Employee emp)
                {
                         if (emp == null)
                        {
                                 return false;
                        }
                         string sql = string.Format( "insert into employee(EmpID,EmpName,EmpCertType,EmpCertNum,EmpPhone,"+
                                 "EmpMobile,EmpAddress,EmpLevel,DepartmentID,Password,UserRightCode,RoleId,UserBirthDate,EmpDiscount) "+
                                 "values('{0}','{1}','{2}','{3}','{4}','{5}','{6}',{7},{8},'{9}','{10}',{11},'{12}',{13})",
                                emp.EmpID,emp.EmpName,emp.EmpCertType,emp.EmpCertNum,emp.EmpPhone,emp.EmpMobile,emp.EmpAddress,
                                emp.EmpLevel,emp.DepartmentID,emp.Password,emp.UserRightCode,emp.RoleID,emp.UserBirthDate, emp.EmpDiscount);

                     return ExecuteCommand(sql) ;
                }

            删除员工的界面代码：

     private void tsmiDelete_Click( object sender, EventArgs e)
                {
                         if (dgrvEmp.SelectedRows.Count < 1)
                        {
                                MessageBox.Show( "选择待修改的员工", "提示");
                                 return;
                        }
                         if (MessageBox.Show( "要删除选中的员工吗？", "提示", MessageBoxButtons.YesNo) == DialogResult.No)
                        {
                                 return;
                        }

                         int num = 0;
                         for ( int i = 0; i < dgrvEmp.SelectedRows.Count; i++)
                        {
                                 string empid = dgrvEmp.SelectedRows[i].Cells[ "empid"].Value.ToString();
                                 if (EmployeeBLL.DeleteEmp(empid))
                                {
                                        num++;
                                }
                        }
                        RefreshEmpList(); //更新列表
                        MessageBox.Show( string.Format( "选中{0}个员工，{1}个删除成功", dgrvEmp.SelectedRows.Count, num), "提示");                        
                }

        DAL代码（删除功能）：

///

                 /// 删除员工
                 ///

                 /// "empid">
                 ///
                 public static bool DeleteEmp( string empid)
                {
                         string sql = "delete from employee where empid = '" +empid + "'";
                         return ExecuteCommand(sql);
                }

           DAL中执行SQL语句：

///

                 /// 执行Sql 命令（增加删除修改）
                 ///

                 /// "sql">
                 ///
                 protected static bool ExecuteCommand( string sql)
                {
                         int re = 0;
                         bool bl;
                         try
                        {
                                re = DBAccess.updateRecords(sql);
                        }
                         catch (SqlException sqle)
                        {
                                re = 0;
                        }
                         finally
                        {
                                bl = (re == 0 ? false : true);
                        }
                         return bl;
                }

           获取员工列表和员工详细信息：

         ///

                 /// 获取员工列表
                 ///

                 ///
                 public static DataTable GetAllEmployee()
                {
                         string sql = "select EmpID,EmpName,EmpCertType,EmpCertNum,EmpPhone,"+
                                 "EmpMobile,EmpAddress,EmpLevel,DepartmentID,Password,UserRightCode,RoleId,UserBirthDate,EmpDiscount from employee";
                        DataTable dt = DBAccess.getDataTable(sql);
                         return dt;
                }
                 public static List GetAllEmployeeList()
                {
                        List lst = new List();
                         string sql = "select EmpID,EmpName,EmpCertType,EmpCertNum,EmpPhone," +
                                 "EmpMobile,EmpAddress,EmpLevel,DepartmentID,Password,UserRightCode,RoleId,UserBirthDate,EmpDiscount from employee";
                        SqlDataReader reader = DBAccess.getDataReader(sql);
                         while (reader.Read())
                        {
                                Employee emp = new Employee();
                                emp.EmpID =reader.IsDBNull(0)?"": reader.GetString(0);
                                emp.EmpName = reader.IsDBNull(1) ? "" : reader.GetString(1);
                                emp.EmpCertType = reader.IsDBNull(2) ? "" : reader.GetString(2);
                                emp.EmpCertNum = reader.IsDBNull(3) ? "" : reader.GetString(3);
                                emp.EmpPhone = reader.IsDBNull(4) ? "" : reader.GetString(4);
                                emp.EmpMobile = reader.IsDBNull(5) ? "" : reader.GetString(5);
                                emp.EmpAddress = reader.IsDBNull(6) ? "" : reader.GetString(6);
                                emp.EmpLevel = reader.IsDBNull(7) ? ( short)0 : reader.GetInt16(7);
                                emp.DepartmentID = reader.IsDBNull(8) ? ( short)0 : reader.GetInt16(8);
                                emp.Password = reader.IsDBNull(9) ? "" : reader.GetString(9);
                                emp.UserRightCode = reader.IsDBNull(10) ? "" : reader.GetString(10);
                                emp.RoleID = reader.IsDBNull(11) ? 0 : reader.GetInt32(11);
                                emp.UserBirthDate =    reader.GetDateTime(12);
                                emp.EmpDiscount = reader.IsDBNull(13) ? ( float)0 : ( float)reader.GetDouble(13);
                                lst.Add(emp);

                        }                        
                         //DataTable dt = DBAccess.getDataTable(sql);
                         return lst;
                }

                 ///

                 /// 获取员工的详细信息
                 ///

                 ///
                 public static List GetAllEmpDetailList()
                {
                        List lst = new List();
                         string sql = "select EmpID,EmpName,EmpCertType,EmpCertNum,EmpPhone," +
                                 "EmpMobile,EmpAddress,EmpLevel,employee.DepartmentID,Password,UserRightCode,employee.RoleId,UserBirthDate,EmpDiscount,checkdepartname,rolename from employee,role,checkDepart" +
                                 "    where employee.roleid = role.roleid and employee.departmentid = checkdepart.checkdepartid";
                        SqlDataReader reader = DBAccess.getDataReader(sql);
                         while (reader.Read())
                        {
                                EmployeeDetail emp = new EmployeeDetail();
                                emp.EmpID = reader.IsDBNull(0) ? "" : reader.GetString(0);
                                emp.EmpName = reader.IsDBNull(1) ? "" : reader.GetString(1);
                                emp.EmpCertType = reader.IsDBNull(2) ? "" : reader.GetString(2);
                                emp.EmpCertNum = reader.IsDBNull(3) ? "" : reader.GetString(3);
                                emp.EmpPhone = reader.IsDBNull(4) ? "" : reader.GetString(4);
                                emp.EmpMobile = reader.IsDBNull(5) ? "" : reader.GetString(5);
                                emp.EmpAddress = reader.IsDBNull(6) ? "" : reader.GetString(6);
                                emp.EmpLevel = reader.IsDBNull(7) ? ( short)0 : reader.GetInt16(7);
                                emp.DepartmentID = reader.IsDBNull(8) ? ( short)0 : reader.GetInt16(8);
                                emp.Password = reader.IsDBNull(9) ? "" : reader.GetString(9);
                                emp.UserRightCode = reader.IsDBNull(10) ? "" : reader.GetString(10);
                                emp.RoleID = reader.IsDBNull(11) ? 0 : reader.GetInt32(11);
                                emp.UserBirthDate = reader.GetDateTime(12);
                                emp.EmpDiscount = reader.IsDBNull(13) ? ( float)0 : ( float)reader.GetDouble(13);
                                emp.DepartName = reader.IsDBNull(14) ? "" : reader.GetString(14);
                                emp.RoleName = reader.IsDBNull(15) ? "" : reader.GetString(15);
                                lst.Add(emp);

                        }
                         //DataTable dt = DBAccess.getDataTable(sql);
                         return lst;
                }