linq 聯合查詢（Join）

查詢人員信息

條件：當此人員信息在部門部門下面則查詢

 public partial class LinqJoin : System.Web.UI.Page
    {
       
        protected void Page_Load(object sender, EventArgs e)
        {
            DataLoad();
            DataInit();
        }
        /// <summary>
        /// Sql查詢
        /// </summary>
        public void DataInit()
        {
            //計算時間差
            Stopwatch watch = new Stopwatch();
            //打開表
            watch.Start();
            using (SqlConnection conn = new SqlConnection(@"server=HAPPY-PC;User ID=sa;Password=happy;database=Exam4.1_OK;Connection Reset=FALSE;Max Pool Size = 512;"))
            {
                conn.Open();

                using (SqlCommand cmd = conn.CreateCommand())
                {
                    //查詢UserId<276234的有部門Id的用戶信息
                    cmd.CommandText = "select a.* from users a inner join Structure c on a.StructureID=c.StructureID where a.UserId<276234";

                    SqlDataAdapter adapter = new SqlDataAdapter();
                    adapter.SelectCommand = cmd;
                    DataSet ds = new DataSet();

                    adapter.Fill(ds);

                    this.GridView1.DataSource = ds;
                    this.GridView1.DataBind();
                    ds.Dispose();

                }
            }
            //關閉表
            watch.Stop();
            //打印時間
            Response.Write("我是第一個："+watch.Elapsed.Milliseconds.ToString());
        }
        /// <summary>
        /// Linq查詢
        /// </summary>
        private  void DataLoad()
        {
            //計算時間差
            Stopwatch watch = new Stopwatch();
            //打開表
            watch.Start();
            using (LinqInnerJoinDataContext ctx = new LinqInnerJoinDataContext("server=HAPPY-PC;User ID=sa;Password=happy;database=Exam4.1_OK;Connection Reset=FALSE;Max Pool Size = 512;"))
            {
                //查詢UserId<276234的有部門Id的用戶信息
                var table = from c in ctx.Users
                            join p in ctx.Structure
                            on c.StructureID equals p.StructureID.ToString()
                            where c.UserID < 276234
                            select c;

                this.GridView2.DataSource = table;
                this.GridView2.DataBind();
            }
            //關閉表
            watch.Stop();
            //顯示時間
            Response.Write("我是第二個:" + watch.Elapsed.Milliseconds.ToString());
        }
    }