linq to sql 小实例

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace LinqToSqlFrom1
{
    using DBSpace;
    using System.Data.Linq;

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

        private void Form1_Load(object sender, EventArgs e)
        {
            DBConn conn = new DBConn("database=Jiang;User ID = Jiang;pwd=admin;server=JIANG-PC\\SQL2010");
            var user = from u in conn.CreateUser where u.Uid < 3 orderby u.Uid select u;

            foreach (var v in user)
                this.listBox1.Items.Add(v.Name.ToString());
        }

        private void listBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            this.listBox2.Items.Clear();
            DBConn conn = new DBConn("database=Jiang;User ID = Jiang;pwd=admin;server=JIANG-PC\\SQL2010");
            var users = from u in conn.CreateUser from us in u.Userid where u.Name == this.listBox1.SelectedItem.ToString() select us;
            foreach (var v in users)
                this.listBox2.Items.Add(v.UserName.ToString());

        }
    }
}
namespace DBSpace
{
    using System.Data.Linq;
    using System.Data.Linq.Mapping;

    public class DBConn : DataContext
    {
        public Table<CDB_MEMBERS> CreateUser;
        public DBConn(string connectionstring)
            : base(connectionstring)
        { }
        public DBConn(IDbConnection connectionstring)
            : base(connectionstring)
        { }
    }
    [Table(Name = "cdb_members")]
    public class CDB_MEMBERS
    {
        [Column(IsPrimaryKey = true)]
        public int Uid;
        [Column]
        public string Name;
        [Column]
        public string Pass;
        private EntitySet<CDB_MEMBERSINFO> userid;
        [Association(Storage = "userid", OtherKey = "Uid")]
        public EntitySet<CDB_MEMBERSINFO> Userid
        {
            get { return this.userid; }
            set { this.userid.Assign(value); }
        }
        [Table(Name = "cdb_membersinfo")]
        public class CDB_MEMBERSINFO
        {
            [Column(IsPrimaryKey = true)]
            public int Fid;
            [Column]
            public string UserName;
            [Column]
            public string Sex;
            [Column]
            public string Age;
            [Column]
            public string Address;
            [Column]
            public string Tel;
            [Column]
            public string Phone;
            [Column]
            public int Uid;

            private EntityRef<CDB_MEMBERS> uid;
            [Association(Storage = "uid", ThisKey = "Uid")]
            public CDB_MEMBERS Members
            {
                get { return this.uid.Entity; }
                set { this.uid.Entity = value; }

            }
        }
    }
}