1、首先创建数据库DataTest,下面为DataTest数据库中的表Admin:
在使用Linq操作数据库时,应当将映入System.Data.Linq命名空间。
2、添加和Admin对应的类Admin(当然也可以用其它类名);
3、用Linq开始对数据库进行常见操作:
using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; using System.Data.Linq.Mapping; using System.Data.Linq; public partial class Linq操作 : System.Web.UI.Page { //在创建DataContext对象是并初始化,其中参数为连接字符串 DataContext dc = new DataContext(@"Data Source=.\SQLEXPRESS;AttachDbFilename=E:\程序练习\LinqInAction\WebLinq\App_Data\DataTest.mdf;Integrated Security=True;User Instance=True"); protected void Page_Load(object sender, EventArgs e) { //调用方法添加数据 InsertData(); Gridview1.DataSource = SelectData(); Gridview1.DataBind(); } //对Admin表进行查询 public IQueryable<Admin> SelectData() { Table<Admin> table=dc.GetTable<Admin>(); var query = from tab in table select tab; return query; }
//插入数据 public void InsertData() { Table<Admin> table = dc.GetTable<Admin>(); Admin admin = new Admin(); admin.ID = 10; admin.UserName = "xiaohai"; admin.PassWord="55555"; table.InsertOnSubmit(admin); dc.SubmitChanges(); }
//删除数据 public void DeleteData() { Table<Admin> table = dc.GetTable<Admin>(); var text=from temp in table //此时的text为Iqueryable<Admin>类型的集合 where temp.ID==10 //注意此处为"==" select temp; foreach (Admin admin in text) { table.DeleteOnSubmit(admin); } dc.SubmitChanges(); } }