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();

}
}
}