/// <summary> /// webform databae first /// </summary> /// <param name="sender"></param> /// <param name="e"></param> protected void Button1_Click(object sender, EventArgs e) { studentttEntities content = new studentttEntities(); var query = from a in content.Set <studnet>().AsNoTracking() join b in content.Set <city>().AsNoTracking() on a.cityid equals b.cityid join c in content.Set <hobby>().AsNoTracking() on a.hobbyid equals c.hobbyid where a.stuname == TextBox1.Text select new { a.stuname, b.cityname, c.hobbyname }; string sql = query.ToString(); Label1.Text = sql; GridView1.DataSource = query.ToList(); GridView1.DataBind(); }
protected void Button1_Click(object sender, EventArgs e) { studentttEntities content = new studentttEntities(); ///linq 表达式 查询 var students1 = from t in content.Set <studnet>().AsNoTracking() where t.stuname == "hans" select new { t.stuname, t.hobbyid, t.cityid }; ///tolist 去 数据库 执行 var query1 = students1.ToList(); GridView1.DataSource = query1; GridView1.DataBind(); ///lambda 表达式查询 var students2 = content.studnet.Where(t => t.stuname == "hans") .Select(t => new { t.stuname, t.hobbyid, t.cityid }); var query2 = students2.ToList(); GridView2.DataSource = query2; GridView2.DataBind(); }