C#将数据库导出成Excel，再从Excel导入到数据库中。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.SqlClient;
using System.IO;
namespace CindyDatabaseProcess
{
    class Program
    {
        static void Main(string[] args)
        {
            System.Data.DataTable dt1 = null;
            System.Data.DataTable dt2 = null;


            SqlConnection conn = null;
            SqlCommand comm = null;
            SqlDataAdapter Adap = null;
            System.Data.DataSet ds = new System.Data.DataSet();

            string sqltext = "select * from product";

            conn = new SqlConnection("server=localhost;database=Cindy;Trusted_Connection=SSPI");
            conn.Open();
            comm = new SqlCommand(sqltext, conn);
            Adap = new SqlDataAdapter(comm);
            //ds = new System.Data.DataSet();
            Adap.Fill(ds, "product1");
            dt1 = ds.Tables["product1"];

            conn = new SqlConnection("server=localhost;database=db_AjaxWall;Trusted_Connection=SSPI");
            conn.Open();
            comm = new SqlCommand(sqltext, conn);
            Adap = new SqlDataAdapter(comm);
            //ds = new System.Data.DataSet();
            Adap.Fill(ds, "product2");
            dt2 = ds.Tables["product2"];


            foreach (System.Data.DataRow dr in dt1.Rows)
            {
                string ziduan1 = dr[0].ToString();
                string ziduan2 = dr[1].ToString();
                string ziduan3 = dr[2].ToString();
                string ziduan4 = dr[3].ToString();

                System.IO.File.AppendAllText(@"C:\Users\lenovo\Desktop\xxx111.csv", ziduan1 + "," + ziduan2 + "," + ziduan3 + "," + ziduan4 + "\r\n", Encoding.UTF8);
            }
            foreach (System.Data.DataRow dr in dt2.Rows)
            {
                string ziduan1 = dr[0].ToString();
                string ziduan2 = dr[1].ToString();
                string ziduan3 = dr[2].ToString();
                string ziduan4 = dr[3].ToString();

                System.IO.File.AppendAllText(@"C:\Users\lenovo\Desktop\xxx111.csv", ziduan1 + "," + ziduan2 + "," + ziduan3 + "," + ziduan4 + "\r\n", Encoding.UTF8);
            }

            string[] aa = File.ReadAllLines(@"C:\Users\lenovo\Desktop\xxx111.csv", Encoding.UTF8);

            StringBuilder sb=new StringBuilder();
            foreach (var item in aa)
            {
                string[] ss = item.Split(',');
                string sql=String.Format("insert into product values({0},'{1}',{2},'{3}');", ss[0], ss[1], ss[2], ss[3]);
                sb.Append(sql);
            }

            comm = new SqlCommand(sb.ToString(), conn);
            int kk = comm.ExecuteNonQuery();
            Console.WriteLine(kk);
            Console.ReadKey();

        }
    }
}