Linq增删查改

 源代码下载地址：http://download.csdn.net/source/3469012

 

首先创建一个不能再简单的数据库

use master
go

if exists(select * from sysdatabases where name='_user')
drop database _user
go

create database _user
go

use _user
go

create table _userinfo
(
_id int identity(1,1) primary key,
_username varchar(50) not null,
_password varchar(50) not null
)
go

insert _userinfo values('test1','test1')
insert _userinfo values('test2','test2')
insert _userinfo values('test3','test3')
insert _userinfo values('test4','test4')
insert _userinfo values('test5','test5')
go

select * from _userinfo

 

然后创建项目，使用linq链接数据库 

命名：DB.dbml

然后创建类DBM.cs用来封装DBDataContext

public class DBM
{
    public static DBDataContext db
    {
        get
        {
            return new DBDataContext();
        }
    }
}

 

再然后创建UserinfoDAL类

public class UserinfoDAL
{
 //增
    public static bool Add(_userinfo u)
    {
        try
        {
            var db = DBM.db;
            db._userinfo.InsertOnSubmit(u);
            db.SubmitChanges();
            return true;
        }
        catch
        {
            return false;           
        }
    }
    //删
    public static bool Del(int id)
    {
        try
        {
            var db = DBM.db;
            _userinfo u = db._userinfo.Single(d => d._id == id);
            db._userinfo.DeleteOnSubmit(u);
            db.SubmitChanges();
            return true;
        }
        catch
        {
            return false;           
        }
    }
    //改
    public static bool Upd(_userinfo u)
    {
        try
        {
            var db = DBM.db;
            _userinfo user = db._userinfo.Single(d => d._id == u._id);
            user._username = u._username;
            user._password = u._password;
            db.SubmitChanges();
            return true;
        }
        catch
        {
            return false;
        }
    }
    //查
    public static List<_userinfo> FindAll()
    {
        return DBM.db._userinfo.ToList();
    }
}

 

最后就是表示层了

页面：LinqToSql.aspx

两个panel

一个放gridview显示

一个是添加的

后台代码：

public partial class LinqToSql : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!this.IsPostBack)
        {
            BD();
        }
    }

    private void BD()
    {
        List<_userinfo> lst = UserinfoDAL.FindAll();
        GridView1.DataSource = lst;
        GridView1.DataBind();
    }
    protected void GridView1_RowDeleting(object sender, GridViewDeleteEventArgs e)
    {
        int id = Convert.ToInt32(GridView1.DataKeys[e.RowIndex].Value);
        if (UserinfoDAL.Del(id))
        {
            msg.Text = "删除成功！";
            BD();
        }
        else
        {
            msg.Text = "删除失败！";
        }
       
    }
    protected void GridView1_RowEditing(object sender, GridViewEditEventArgs e)
    {
        GridView1.EditIndex = e.NewEditIndex;
        BD();
    }
    protected void GridView1_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
    {
        GridView1.EditIndex = -1;
        BD();
    }
    protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)
    {
        _userinfo u = new _userinfo();
        u._id = Convert.ToInt32(GridView1.DataKeys[GridView1.EditIndex].Value);
        u._username = (GridView1.Rows[GridView1.EditIndex].Cells[1].Controls[0] as TextBox).Text;
        u._password = (GridView1.Rows[GridView1.EditIndex].Cells[2].Controls[0] as TextBox).Text;
        if (UserinfoDAL.Upd(u))
        {
            GridView1.EditIndex = -1;
            BD();
            msg.Text = "修改成功！";
        }
        else
        {
            msg.Text = "修改失败！";
        }
    }
    protected void LinkButton1_Click(object sender, EventArgs e)
    {
        Panel1.Visible = false;
        Panel2.Visible = true;
    }
    protected void Button2_Click(object sender, EventArgs e)
    {
        Panel2.Visible = false;
        Panel1.Visible = true;
        BD();
    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        _userinfo u = new _userinfo();
        u._username = TextBox1.Text;
        u._password = TextBox2.Text;
        if (UserinfoDAL.Add(u))
        {
            TextBox1.Text = "";
            TextBox2.Text = "";
            msg2.Text = "增加成功！";
        }
        else
        {
            msg2.Text = "增加失败！";
        }
    }
}

来源：https://www.cnblogs.com/Kung/archive/2011/12/29/Linq.html