EF方式增、删、改、查(基本使用)

右击项目——添加——新建项——数据（C#）——选择ADO.NET实体数据模型——点击添加——然后根据实体数据模型向导来一步步的做。

用到的表

 using System;
 using System.Data;
 using System.Linq;
 using System.Windows.Forms;

 namespace WindowsFormsApp1
 {
     public partial class Form1 : Form
     {
         public Form1()
         {
             InitializeComponent();
         }

         private void simpleButton1_Click(object sender, EventArgs e)
         {
             XtraForm1 xtraForm1 = new XtraForm1();
             xtraForm1.ShowDialog();
         }
         //查询
         private void simpleButton2_Click(object sender, EventArgs e)
         {
             using (NorthwindEntities db = new NorthwindEntities())
             {
                 var cust = from c in db.Region select c;
                 gridControl1.DataSource = cust.ToList();
             }
         }
         //增加
         private void simpleButton1_Click_1(object sender, EventArgs e)
         {
             using (NorthwindEntities db = new NorthwindEntities())
             {
                 Region region = new Region();
                 region.RegionID =int.Parse(textEdit1.Text.Trim());
                 region.RegionDescription = textEdit2.Text.Trim();
                 db.Region.Add(region);
                 int rows = db.SaveChanges();
                 MessageBox.Show(rows.ToString());
             }
         }
         //修改
         private void simpleButton3_Click(object sender, EventArgs e)
         {
             using (NorthwindEntities db = new NorthwindEntities())
             {
                 int id = Convert.ToInt32(textEdit1.Text);
                 Region region = db.Region.Where(i => i.RegionID == id).FirstOrDefault();
                 if (region != null)
                 {
                     region.RegionDescription = textEdit2.Text;
                     int rows = db.SaveChanges();
                     MessageBox.Show(rows.ToString());
                 }
             }
         }
         //删除
         private void simpleButton4_Click(object sender, EventArgs e)
         {
             using (NorthwindEntities db = new NorthwindEntities())
             {
                 int id = Convert.ToInt32(textEdit1.Text);
                 Region region = db.Region.Where(i => i.RegionID == id).FirstOrDefault();
                 if (region != null)
                 {
                     db.Region.Remove(region);
                     int rows = db.SaveChanges();
                     MessageBox.Show(rows.ToString());
                 }
             }
         }
         //单元格取值
         private void gridView1_RowCellClick(object sender, DevExpress.XtraGrid.Views.Grid.RowCellClickEventArgs e)
         {
             var index = gridView1.GetFocusedDataSourceRowIndex();
             textEdit1.Text = gridView1.GetRowCellValue(index, "RegionID").ToString().Trim();
             textEdit2.Text = gridView1.GetRowCellValue(index, "RegionDescription").ToString().Trim();
         }
     }
 }

补充：批量增加数据

         //批量增加数据
         public void AddRange()
         {
             using (Northwind db = new Northwind())
             {
                 List<Region> regions = new List<Region>();
                 regions.Add(new Region { RegionID = , RegionDescription = "济南" });
                 regions.Add(new Region { RegionID = , RegionDescription = "合肥" });
                 regions.Add(new Region { RegionID = , RegionDescription = "天津" });
                 db.Region.AddRange(regions);
                 Response.Write(db.SaveChanges());
             }
         }

界面