第一步 新建数据库
新建数据库TestDB2
第二步 ADO.NET实体数据模型
新建空的ADO.NET实体数据模型
新增实体(表)和类型(字段)
右键TestModel.edmx界面点击“根据模型生成数据库”,执行生成的TestModel.edmx.sql文件中的SQL语句。
第三步 增删改查
using System; using System.Data; using System.Linq; using System.Windows.Forms; namespace EFDEMO3 { public partial class Form1 : Form { TestModelContainer entity = new TestModelContainer(); public Form1() { InitializeComponent(); } /// <summary> /// 新增 /// </summary> private void Add() { T_Action model = new T_Action() { Name = DateTime.Now.ToString("yyyy-MM-dd hh:mm:ss") }; entity.T_Action.Add(model); entity.SaveChanges(); Query(); } /// <summary> /// 删除 /// </summary> private void Delete() { if (listBox1.SelectedItem == null) { return; } int id = Convert.ToInt32(listBox1.SelectedItem.ToString().Split(‘-‘)[0]); T_Action model = entity.T_Action.Where(a => a.ID == id).FirstOrDefault(); if (model != null) { entity.Entry(model).State = EntityState.Deleted; entity.SaveChanges(); Query(); } } /// <summary> /// 修改 /// </summary> private void Edit() { if (listBox1.SelectedItem == null) { return; } int id = Convert.ToInt32(listBox1.SelectedItem.ToString().Split(‘-‘)[0]); T_Action model = entity.T_Action.Where(a => a.ID == id).FirstOrDefault(); if (model != null) { model.Name = DateTime.Now.ToString("yyyy-MM-dd hh:mm:ss"); entity.Entry(model).State = EntityState.Modified; entity.SaveChanges(); Query(); } } /// <summary> /// 查询 /// </summary> private void Query() { listBox1.Items.Clear(); var expr = entity.T_Action; foreach (var item in expr) { listBox1.Items.Add(string.Format("{0}-{1}", item.ID, item.Name)); } } private void toolStripButton1_Click(object sender, EventArgs e) { Add(); } private void toolStripButton4_Click(object sender, EventArgs e) { Edit(); } private void toolStripButton3_Click(object sender, EventArgs e) { Delete(); } private void toolStripButton2_Click(object sender, EventArgs e) { Query(); } } }
时间: 2024-10-14 08:16:43