数据集中的LinqToSql查询

Question

您好，我尝试将C＃中的SQL查询转换为LinqToSql。我的代码是从SQL Server获取2个表，并将它们放在这样的DataSet中：

private void Valid_Cmd_Btn_Click(object sender, RoutedEventArgs e)
    {
        int numCmd = Convert.ToInt32(NumCmd_TB.Text);

        #region ARTICLES
        comm = new SqlCommand("SELECT * FROM ARTICLES", conn);
        SqlDataAdapter dap = new SqlDataAdapter(comm);
        DataTable dt = new DataTable("ARTICLES");
        dap.Fill(dt);
        #endregion

        #region CMD_DET
        comm = new SqlCommand("SELECT * FROM CMD_DET", conn);
        SqlDataAdapter dap1 = new SqlDataAdapter(comm);
        DataTable dt1 = new DataTable("CMD_DET");
        dap1.Fill(dt1);
        #endregion

        #region CMD_ENT
        comm = new SqlCommand($"SELECT * FROM CMD_ENT WHERE CMD_ENT_ID= {numCmd}", conn);
        SqlDataAdapter dap2 = new SqlDataAdapter(comm);
        DataTable dt2 = new DataTable("CMD_ENT");
        dap2.Fill(dt2);
        #endregion

         DataSet ds = new DataSet();
        ds.Tables.Add(dt);
        ds.Tables.Add(dt1);
        ds.Tables.Add(dt2);
    }

现在我想对LinqToSql语法做同样的事情：

private void Valid_Cmd_Btn_Click(object sender, RoutedEventArgs e)
    {
         DataClasses1DataContext dc = new DataClasses1DataContext();
        var articles = from a in dc.ARTICLES
                       select a;
                       // How to put this in a Datable ?

                        DataClasses1DataContext dc1 = new DataClasses1DataContext();
        var det = from d in dc.CMD_DET
                       select d;
                       // How to put this in a Datable ?

                       //...

                       // and then like in Sql query how to get those 2 tables in a Dataset ??
    }