用自己设计的表（包括主键，外键约束）填充DataSet类

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Data.SqlClient;
using System.Data;

namespace ConsoleApplication2
{
    class Program
    {
        static void Main(string[] args)
        {
            DataSet ds = new DataSet();
            ds.Tables.Add(createbuildingtable());
            ds.Tables.Add(createroomtable());
            //定义外键约束
            DataColumn child = ds.Tables["room"].Columns["buildingid"];
            DataColumn parent=ds.Tables["building"].Columns["buildingid"];
            ForeignKeyConstraint fc = new ForeignKeyConstraint("fc", parent, child);//主(building)表从(room)表之间建立外键关联对象fc,约束名为fc
            ds.Tables["room"].Constraints.Add(fc);//必须添加到子表中的约束集合（Constraints）中
            ////申明基类数组，存放表中的数据
            object[] dt1=new object[2];
            object[] dt2 = new object[3];
            //为基类数组赋值
            dt1[0] = 1;
            dt1[1] = "如家";
            dt2[0] = 206;
            dt2[1] = "翰墨轩";
            dt2[2] = 1;
            ////将数据加到表的行中去
            ds.Tables["building"].Rows.Add(dt1);
            ds.Tables["room"].Rows.Add(dt2);
            //打印两个表中的数据
            foreach(DataRow x in ds.Tables["building"].Rows)
                foreach (DataColumn y in ds.Tables["building"].Columns)
                {
                    Console.WriteLine("{0}:{1}", y.ColumnName, x[y]);
                }
            foreach (DataRow x in ds.Tables["room"].Rows)
                foreach (DataColumn y in ds.Tables["room"].Columns)
                {
                    Console.WriteLine("{0}:{1}", y.ColumnName, x[y]);
                }
            ds.Relations.Add("rooms", ds.Tables["building"].Columns["buildingid"], ds.Tables["room"].Columns["buildingid"]);//Relations:用于将表链接起来并允许从父表浏览到子表的关系的集合
            Console.WriteLine("________________________");
            foreach (DataRow building in ds.Tables["building"].Rows)
            {
                DataRow[] children = building.GetChildRows("rooms");//使用 关系集合 的指定 关系名称RelationName(rooms)，取得 DataRow 的子資料列
                int count = children.Length;
                Console.WriteLine("building{0} contains {1} room{2}", building["name"], count, count > 1 ? "s" : "");
                foreach (DataRow row in children)
                    Console.WriteLine("room:{0}", row["name"]);
            }
        }

        private static DataTable createroomtable()
        {
            DataTable room = new DataTable("room");//申请一个内存表
            //为内存表添加列
            room.Columns.Add(new DataColumn("roomid", typeof(int)));
            room.Columns.Add(new DataColumn("name", typeof(string)));
            room.Columns.Add(new DataColumn("buildingid", typeof(int)));
            //设置主键约束的另一种方法，使用UniqueConstraint
            //room.Constraints.Add(new UniqueConstraint(room.Columns["roomid"]));//room.Constraints:由该表维护的约束的集合
            DataColumn[] a = new DataColumn[1];//定义datacolumn对象的数组
            a[0] = room.Columns["roomid"];
            room.PrimaryKey = a;//定义主键 PrimaryKey:获取或设置充当数据表主键的列的数组,他的类型为datacolumn对象的数组
            return room;
        }

        private static DataTable createbuildingtable()
        {
            DataTable building = new DataTable("building");
            building.Columns.Add(new DataColumn("buildingid", typeof(int)));
            building.Columns.Add(new DataColumn("name", typeof(string)));
            DataColumn[] a = new DataColumn[1];//定义datacolumn对象的数组
            a[0] = building.Columns["buildingid"];
            building.PrimaryKey =a;//定义主键 PrimaryKey:获取或设置充当数据表主键的列的数组,他的类型为datacolumn对象的数组
            return building;
        }
    }
}