DataSet 比较 select

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;

namespace DataSetConr
{
    class Program
    {

        public static void AddDataSetData(DataSet ds)
        {
            ds.Reset();
            DataTable dt = new DataTable();
            DataColumn dc = new DataColumn("guid", typeof(Guid));
            DataColumn dc2 = new DataColumn("show", typeof(Boolean));
            DataColumn dc3 = new DataColumn("isnull", typeof(Boolean));
            dt.Columns.Add(dc); dt.Columns.Add(dc2); dt.Columns.Add(dc3);
            DataRow dr = dt.NewRow();
            dr.BeginEdit();
            dr["guid"] = Guid.NewGuid();
            dr["show"] = true;
            dr["isnull"] = false;
            dr.EndEdit();
            dt.Rows.Add(dr);
            ds.Tables.Add(dt);
        }

        static void Main(string[] args)
        {

            DataSet ds = new DataSet();
            DataSet ds2 = new DataSet();
            AddDataSetData(ds);
            AddDataSetData(ds2);
            foreach (DataRow item in ds.Tables[0].Rows)
            {
                //查看A在B中是否存在
                DataRow[] rows = ds2.Tables[0].Select(string.Format("show={0} and isnull={1}",item["show"].ToString(),item["isnull"].ToString()));
                if (rows.Length==0)
                {
                   
                }
            }
        }
    }
}