Linq 在 ADO.NET 的 使用

using System;
using System.Data;

namespace LinqUseInAdoNetDemo
{
    /// <summary>
    ///     Linq 在 ADO.NET 的 使用
    ///     https://www.cnblogs.com/LifeDecidesHappiness/p/8079142.html
    ///     2021-9-15
    /// </summary>
    internal class Program
    {
        private static void Main()
        {
            Console.Title = "Linq 在 ADO.NET 的 使用";

            LinqInAdoNetDemo();

            Console.ReadKey();
        }

        private static void LinqInAdoNetDemo()
        {
            var dt = GetDataTable();

            //  Lambda Expression
            //  var query = dt.AsEnumerable().OrderBy(x => x.Field<int>("Age"));

            //  Linq Expression
            var query = from x in dt.AsEnumerable()
                orderby x.Field<int>("Age")
                select x;

            foreach (var dataRow in query)
                Console.WriteLine("【编号】{0}  \t 【姓名】{1} \t 【年龄】{2}", dataRow.Field<int>("Id"),
                    dataRow.Field<string>("Name"), dataRow.Field<int>("Age"));
        }

        /// <summary>
        ///     手动创建 DataTable
        /// </summary>
        /// <returns></returns>
        public static DataTable GetDataTable()
        {
            var dt = new DataTable();

            // Columns
            dt.Columns.AddRange(new[]
            {
                new DataColumn("Id", typeof(int)),
                new DataColumn("Name", typeof(string)),
                new DataColumn("Age", typeof(int))
            });

            // Data Rows
            var row = dt.NewRow();
            row["Id"] = 1;
            row["Name"] = "LDH";
            row["Age"] = 28;
            dt.Rows.Add(row);

            row = dt.NewRow();
            row["Id"] = 2;
            row["Name"] = "Jack";
            row["Age"] = 50;
            dt.Rows.Add(row);

            row = dt.NewRow();
            row["Id"] = 3;
            row["Name"] = "Jason";
            row["Age"] = 18;
            dt.Rows.Add(row);

            return dt;
        }
    }
}