综合查询员工和datetime.now和datetime.today区别

一：综合查询图

二：EmployeeListWindow.cs代码

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using HRMSys.DAL;
using HRMSys.Model;
using System.Data.SqlClient;

namespace HYMSys.UI.EmployeeMgr
{
    public partial class EmployeeListWindow : Form
    {
        public EmployeeListWindow()
        {
            InitializeComponent();
        }
        /// <summary>
        /// 加载所有信息
        /// </summary>
        public EmployeeList[] load()
        {
            EmployeeDAL de = new EmployeeDAL();
            
           return de.ListAll();
           

            
        }
       
        /// <summary>
        /// 添加员工
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void toolsb_add_Click(object sender, EventArgs e)
        {
            EmployeeEditWindow edit = new EmployeeEditWindow();
            edit.IsAdd = true;
            edit.ShowDialog();

            if (edit.IsLoad == true)
            {
                dataGridView1.DataSource = load();
            }

        }
        /// <summary>
        /// 删除员工
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void toolsb_delete_Click(object sender, EventArgs e)
        {
            Guid id=(Guid)dataGridView1.CurrentRow.Cells[0].Value;
            string name=(string)dataGridView1.CurrentRow.Cells[2].Value;//这里的cell是相对于list员工操作窗口上name这列,即使第二行
            if (MessageBox.Show("真的要删除---"+name+"---吗?","警告!",MessageBoxButtons.OKCancel)==DialogResult.OK)
            {
                EmployeeDAL dal = new EmployeeDAL();
                dal.DeleteById(id);
                dataGridView1.DataSource = load();
            }
            
        }
        /// <summary>
        /// 修改员工信息
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void toolsb_edit_Click(object sender, EventArgs e)
        {
            EmployeeEditWindow edit = new EmployeeEditWindow();
           edit.EditId = (Guid)dataGridView1.CurrentRow.Cells[0].Value;
           edit.IsAdd = false;
            edit.ShowDialog();
            if (edit.IsLoad == true)
            {
                dataGridView1.DataSource = load();
            }

        }
        /// <summary>
        /// 自动加载所有员工信息
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void EmployeeListWindow_Load(object sender, EventArgs e)
        {
            DepartmentDAL dal = new DepartmentDAL();
            cb_depart.DataSource = dal.ListAll();
            cb_depart.DisplayMember = "Name";
            cb_depart.ValueMember = "Id";
            //cb_depart.SelectedValue=

            dtp_indate.Value = DateTime.Today.AddMonths(-1);
            dtp_enddate.Value = DateTime.Today;

            
            dataGridView1.DataSource= load();


            
        }
        /// <summary>
        /// 综合查询
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button1_Click(object sender, EventArgs e)
        {
            List<string> wherelist = new List<string>();
            List<SqlParameter> parameter = new List<SqlParameter>();
            if (ckb_name.Checked == true) 
            {
                wherelist.Add("Name=@Name");
                parameter.Add(new SqlParameter("@Name",tb_name.Text));
 
            }
            if (ckb_indate.Checked == true)
            {
                wherelist.Add("InDate>=@InDateStart and InDate<=@InDateEnd");
                parameter.Add(new SqlParameter("@InDateStart",dtp_indate.Value));
                parameter.Add(new SqlParameter("@InDateEnd",dtp_enddate.Value));
            }
            if (ckb_depart.Checked == true)
            {
                wherelist.Add("DepartmentId=@DepartmentId");
                parameter.Add(new SqlParameter("@DepartmentId",cb_depart.SelectedValue));
            }



            string whereSql=string.Join(" and ",wherelist);
            string Sql="select * from T_Employee";
            if (whereSql.Length > 0)
            {
                Sql = Sql + " where " + whereSql;
            }
            EmployeeDAL dal = new EmployeeDAL();
            dataGridView1.DataSource= dal.SearchBySome(Sql, parameter);
           



        }
    }
}

三：EmployeeDAL.cs代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using HRMSys.Model;
using System.Data;
using System.Data.SqlClient;

namespace HRMSys.DAL
{
    public class EmployeeDAL
    {
        /// <summary>
        /// 将表的列转换为EmployeeList对象的字段
        /// </summary>
        /// <param name="row"></param>
        /// <returns></returns>
        public EmployeeList ToEmployeeListModel(DataRow row)
        {
            EmployeeList employee = new EmployeeList();
            employee.Address = (string)row["Address"];
            employee.BaseSalary = (int)row["BaseSalary"];
            employee.BirthDay = (DateTime)row["BirthDay"];
            employee.ContractEndDay = (DateTime)row["ContractEndDay"];
            employee.ContractStartDay = (DateTime)row["ContractStartDay"];
            employee.Department =GetNameByGuidDE( (Guid)row["DepartmentId"]);//////
            employee.Education= GetNameByGuidID((Guid)row["EducationId"]);/////
            employee.Email = (string)row["Email"];
            employee.EmergencyContact = (string)sqlhelper.FromDbValue(row["EmergencyContact"]);
            employee.Gender = GetNameByGuidID((Guid)row["GenderId"]);///////
            employee.Id = (Guid)row["Id"];
            employee.IdNum = (string)row["IdNum"];
            employee.InDate = (DateTime)row["InDate"];
            employee.Major = (string)sqlhelper.FromDbValue(row["Major"]);
            employee.Marriage = GetNameByGuidID((Guid)row["MarriageId"]);/////////
            employee.Name = (string)row["Name"];
            employee.Nationality = (string)row["Nationality"];
            employee.NativeAddr = (string)row["NativeAddr"];
            employee.Number = (string)row["Number"];
            employee.PartyStatus = GetNameByGuidID((Guid)row["PartyStatusId"]);//////
            employee.Position = (string)row["Position"];
            employee.Remarks = (string)sqlhelper.FromDbValue(row["Remarks"]);
            employee.Resume = (string)sqlhelper.FromDbValue(row["Resume"]);
            employee.School = (string)sqlhelper.FromDbValue(row["School"]);
            employee.TelNum = (string)row["TelNum"];
            employee.IsStopped = (bool)row["IsStopped"];
            //todo:如果员工非常多，那么Photo会增加内存占用
            employee.Photo = (byte[])sqlhelper.FromDbValue(row["Photo"]);
            return employee;
        }



        /// <summary>
        /// 将表转换为Employee对象的字段
        /// </summary>
        /// <param name="row"></param>
        /// <returns></returns>
        public Employee ToEmployeeModel(DataRow row)
        {
            Employee employee = new Employee();
            employee.Address = (string)row["Address"];
            employee.BaseSalary = (int)row["BaseSalary"];
            employee.BirthDay = (DateTime)row["BirthDay"];
            employee.ContractEndDay = (DateTime)row["ContractEndDay"];
            employee.ContractStartDay = (DateTime)row["ContractStartDay"];
            employee.DepartmentId = (Guid)row["DepartmentId"];//////
            employee.EducationId = (Guid)row["EducationId"];/////
            employee.Email = (string)row["Email"];
            employee.EmergencyContact = (string)sqlhelper.FromDbValue(row["EmergencyContact"]);
            employee.GenderId = (Guid)row["GenderId"];///////
            employee.Id = (Guid)row["Id"];
            employee.IdNum = (string)row["IdNum"];
            employee.InDate = (DateTime)row["InDate"];
            employee.Major = (string)sqlhelper.FromDbValue(row["Major"]);
            employee.MarriageId = (Guid)row["MarriageId"];/////////
            employee.Name = (string)row["Name"];
            employee.Nationality = (string)row["Nationality"];
            employee.NativeAddr = (string)row["NativeAddr"];
            employee.Number = (string)row["Number"];
            employee.PartyStatusId = (Guid)row["PartyStatusId"];//////
            employee.Position = (string)row["Position"];
            employee.Remarks = (string)sqlhelper.FromDbValue(row["Remarks"]);
            employee.Resume = (string)sqlhelper.FromDbValue(row["Resume"]);
            employee.School = (string)sqlhelper.FromDbValue(row["School"]);
            employee.TelNum = (string)row["TelNum"];
            employee.IsStopped = (bool)row["IsStopped"];
            //todo:如果员工非常多，那么Photo会增加内存占用
            employee.Photo = (byte[])sqlhelper.FromDbValue(row["Photo"]);
            return employee;
        }
        /// <summary>
        /// 软删除指定id的员工信息
        /// </summary>
        /// <param name="id"></param>
        public void DeleteById(Guid id)
        {
            //update T_Operator set IsLocked=@IsLocked  where Id=@Id"
           int i= sqlhelper.ExecuteNon("update T_Employee set IsStopped =1 where Id=@Id",
                new SqlParameter ("@Id",id));
            
 
        }
        /// <summary>
        /// 指定id从idname中取得名字
        /// </summary>
        /// <param name="id"></param>
        /// <returns></returns>
        public string GetNameByGuidID(Guid id)
        {
            DataTable table= sqlhelper.datatable("select Name from T_IdName where Id=@Id",
                new SqlParameter("@Id",id));
            DataRow row = table.Rows[0];
            return (string) row["Name"];

        }
        /// <summary>
        /// 指定id从department中取得名字
        /// </summary>
        /// <param name="id"></param>
        /// <returns></returns>
        public string GetNameByGuidDE(Guid id)
        {
            DataTable table = sqlhelper.datatable("select Name from T_Department where Id=@Id",
                new SqlParameter("@Id", id));
            DataRow row = table.Rows[0];
            return (string)row["Name"];
        }
        /// <summary>
        /// 得到所有未删除的员工的所有信息
        /// </summary>
        /// <returns>Employee数组</returns>
        public EmployeeList[] ListAll()
        {
            DataTable table = sqlhelper.datatable("select * from T_Employee where IsStopped=0");
            EmployeeList[] items = new EmployeeList[table.Rows.Count];
            for (int i = 0; i < table.Rows.Count; i++)
            {
                EmployeeList employee = ToEmployeeListModel(table.Rows[i]);
                items[i] = employee;
            }
            return items;
        }
        /// <summary>
        /// 得到指定id的员工信息
        /// </summary>
        /// <param name="id"></param>
        /// <returns>Employee对象</returns>
        public Employee GetById(Guid id)
        {
            DataTable table = sqlhelper.datatable("select * from T_Employee where Id=@Id",
                new SqlParameter("@Id", id));
            if (table.Rows.Count == 1)
            {
                return ToEmployeeModel(table.Rows[0]);
            }
            else
            {
                throw new Exception();
            }
        }
        /// <summary>
        /// 插入一条员工数据
        /// </summary>
        /// <param name="employee"></param>
        public void Insert(Employee employee)
        {
            sqlhelper.ExecuteNon(@"INSERT INTO [T_Employee]
           ([Id],[Number],[Name],[BirthDay],[InDate],[MarriageId],[PartyStatusId],[Nationality]
           ,[NativeAddr],[EducationId],[Major],[School],[Address],[BaseSalary],[Email]
           ,[IdNum],[TelNum],[EmergencyContact],[DepartmentId],[Position],[ContractStartDay]
           ,[ContractEndDay],[Resume],[Remarks],[IsStopped],[GenderId],Photo)
            VALUES(newid(),@Number,@Name,@BirthDay,@InDate,@MarriageId,@PartyStatusId,@Nationality
           ,@NativeAddr,@EducationId,@Major,@School,@Address,@BaseSalary,@Email
           ,@IdNum,@TelNum,@EmergencyContact,@DepartmentId,@Position,@ContractStartDay
           ,@ContractEndDay,@Resume,@Remarks,0,@GenderId,@Photo)", new SqlParameter("@Number", employee.Number)
                                                         , new SqlParameter("@Name", employee.Name)
                                                         , new SqlParameter("@BirthDay", employee.BirthDay)
                                                         , new SqlParameter("@InDate", employee.InDate)
                                                         , new SqlParameter("@MarriageId", employee.MarriageId)
                                                         , new SqlParameter("@PartyStatusId", employee.PartyStatusId)
                                                         , new SqlParameter("@Nationality", employee.Nationality)
                                                         , new SqlParameter("@NativeAddr", employee.NativeAddr)
                                                         , new SqlParameter("@EducationId", employee.EducationId)
                                                         , new SqlParameter("@Major", sqlhelper.ToDbValue(employee.Major))
                                                         , new SqlParameter("@School", sqlhelper.ToDbValue(employee.School))
                                                         , new SqlParameter("@Address", employee.Address)
                                                         , new SqlParameter("@BaseSalary", employee.BaseSalary)
                                                         , new SqlParameter("@Email", sqlhelper.ToDbValue(employee.Email))
                                                         , new SqlParameter("@IdNum", employee.IdNum)
                                                         , new SqlParameter("@TelNum", employee.TelNum)
                                                         , new SqlParameter("@EmergencyContact", sqlhelper.ToDbValue(employee.EmergencyContact))
                                                         , new SqlParameter("@DepartmentId", employee.DepartmentId)
                                                         , new SqlParameter("@Position", employee.Position)
                                                         , new SqlParameter("@ContractStartDay", employee.ContractStartDay)
                                                         , new SqlParameter("@ContractEndDay", employee.ContractEndDay)
                                                         , new SqlParameter("@Resume", sqlhelper.ToDbValue(employee.Resume))
                                                         , new SqlParameter("@Remarks", sqlhelper.ToDbValue(employee.Remarks))
                                                         , new SqlParameter("@GenderId", employee.GenderId)
                                                        , new SqlParameter("@Photo", SqlDbType.Image) {Value= sqlhelper.ToDbValue(employee.Photo) }//需要指定专门image的类型,数据库不认识,
                                                        );

        }
        /// <summary>
        /// 更新一条员工数据数据
        /// </summary>
        /// <param name="employee"></param>
         public void Update(Employee employee)
        {
            sqlhelper.ExecuteNon(@"Update T_Employee set 
            [Number]=@Number,[Name]=@Name,[BirthDay]=@BirthDay,[InDate]=@InDate,
            [MarriageId]=@MarriageId,[PartyStatusId]=@PartyStatusId,[Nationality]=@Nationality,
            [NativeAddr]=@NativeAddr,[EducationId]=@EducationId,[Major]=@Major,[School]=@School,
            [Address]=@Address,[BaseSalary]=@BaseSalary,[Email]=@Email,
            [IdNum]=@IdNum,[TelNum]=@TelNum,[EmergencyContact]=@EmergencyContact,
            [DepartmentId]=@DepartmentId,[Position]=@Position,[ContractStartDay]=@ContractStartDay,
            [ContractEndDay]=@ContractEndDay,[Resume]=@Resume,[Remarks]=@Remarks,[GenderId]=@GenderId,
            photo=@Photo
            
            Where Id=@Id", new SqlParameter("@Number", employee.Number)
                                                         , new SqlParameter("@Name", employee.Name)
                                                         , new SqlParameter("@BirthDay", employee.BirthDay)
                                                         , new SqlParameter("@InDate", employee.InDate)
                                                         , new SqlParameter("@MarriageId", employee.MarriageId)
                                                         , new SqlParameter("@PartyStatusId", employee.PartyStatusId)
                                                         , new SqlParameter("@Nationality", employee.Nationality)
                                                         , new SqlParameter("@NativeAddr", employee.NativeAddr)
                                                         , new SqlParameter("@EducationId", employee.EducationId)
                                                         , new SqlParameter("@Major", sqlhelper.ToDbValue(employee.Major))
                                                         , new SqlParameter("@School", sqlhelper.ToDbValue(employee.School))
                                                         , new SqlParameter("@Address", employee.Address)
                                                         , new SqlParameter("@BaseSalary", employee.BaseSalary)
                                                         , new SqlParameter("@Email", sqlhelper.ToDbValue(employee.Email))
                                                         , new SqlParameter("@IdNum", employee.IdNum)
                                                         , new SqlParameter("@TelNum", employee.TelNum)
                                                         , new SqlParameter("@EmergencyContact", sqlhelper.ToDbValue(employee.EmergencyContact))
                                                         , new SqlParameter("@DepartmentId", employee.DepartmentId)
                                                         , new SqlParameter("@Position", employee.Position)
                                                         , new SqlParameter("@ContractStartDay", employee.ContractStartDay)
                                                         , new SqlParameter("@ContractEndDay", employee.ContractEndDay)
                                                         , new SqlParameter("@Resume", sqlhelper.ToDbValue(employee.Resume))
                                                         , new SqlParameter("@Remarks", sqlhelper.ToDbValue(employee.Remarks))
                                                         , new SqlParameter("@GenderId", employee.GenderId)
                                                          , new SqlParameter("@Photo", SqlDbType.Image) {Value= sqlhelper.ToDbValue(employee.Photo) }//需要指定专门image的类型,数据库不认识,
                                                         , new SqlParameter("@Id", employee.Id)
                                                        );
        }
        /// <summary>
        /// 综合查询
        /// </summary>
        /// <param name="sql"></param>
        /// <param name="parameter"></param>
        /// <returns></returns>
         public EmployeeList[] SearchBySome(string sql, List<SqlParameter> parameter)
         {
             DataTable table= sqlhelper.datatable(sql, parameter.ToArray());
             EmployeeList[] items = new EmployeeList[table.Rows.Count];
             for (int i = 0; i < table.Rows.Count; i++)
             {
                 items[i] = ToEmployeeListModel(table.Rows[i]);
             }

             return items;
         }
    
    }

}

四：datetime.now和datetime.today区别

datetime.now 表示现在的最准确的时间，精确到秒
datetime.today 表示当天的时间，精确到天