从SQLserver中导出表数据到Access

每篇随便都得有个背景吧，这次做一个项目时，突然碰到这个样一个问题，需要将本地sqlserver中的数据导出到access后，再传输access数据库，所以就在想怎样实现这样的操作。后面经过在网上查找了一些资料结合以前的知识，搞了这样一个东西出来；

        /// <summary>
        /// 从sqlserver中导出数据到access
        /// state=0 Jzjl 导出菜品信息表
        /// state=1 lbxf_jz 导出收银信息表
        /// </summary>
        /// <param name="host"></param>
        /// <param name="name"></param>
        /// <param name="password"></param>
        /// <param name="root"></param>
        static void BackupA(string tablename, int state, string connection = "Data Source=.;Initial Catalog=mpcy;Integrated Security=True")
        {
            string path = System.AppDomain.CurrentDomain.SetupInformation.ApplicationBase;
            string file = "mpcy.model";
            string root = path + file;

            Console.WriteLine("文件路径:" + root);
            //备份Access数据库
            if (state == 0) { tablename = "Jzjl"; chkandcrt(root); } else { tablename = "lbxf_jz"; }

            root = BakPath + "\mpcy.dat";
            string accesssqlconn = @"Provider=Microsoft.ACE.OLEDB.12.0;Jet OLEDB:DataBase Password=xhjxjf168;Data Source=" + root + ";";
            //SqlHelper.ConnectionString = string.Format("Data Source={0};Initial Catalog={1};User ID={2};Password={3}", "127.0.0.1", "mpcyTemp", "sa", "12345");
            //connection = string.Format("Data Source=.;Initial Catalog={0};Integrated Security=True", "mpcyTemp");
            SqlHelper.ConnectionString = connection;
            //从sqlserver中读出数据到datatable
            OleDbConnection conn = new OleDbConnection(accesssqlconn);
            OleDbCommand cmd = conn.CreateCommand();
            try
            {
                DataTable user = SqlHelper.ExecuteTable(CommandType.Text, string.Format("select * from {0}", tablename), null);
                int i = 0;
                if (user.Rows.Count > 0)
                {
                    using (conn)
                    {
                        using (cmd)
                        {
                            conn.Open();

                            //每次导入前，先清空数据库表
                            string sql = string.Format("delete * from {0}", tablename); cmd.CommandText = sql; cmd.ExecuteNonQuery();

                            OleDbDataAdapter adp = new OleDbDataAdapter(); adp.SelectCommand = new OleDbCommand(string.Format("select * from {0}", tablename), conn); OleDbCommandBuilder cb = new OleDbCommandBuilder(adp); DataSet data = new DataSet();
                            //加载access中的数据表，并通过追加的方式放入dataset中
                            adp.Fill(data);
                            for (int j = 0; j < user.Rows.Count; j++)
                            {
                                //for (int l = 0; l < user.Columns.Count; l++)
                                //{
                                //    if (l > user.Columns.Count - 1)
                                //        break;
                                DataRow dr = data.Tables[0].NewRow();
                                for (int k = 0; k < dr.Table.Columns.Count; k++)
                                {
                                    Type typ = user.Rows[j][k].GetType();
                                    if (typ == typeof(double) || typ == typeof(int) || typ == typeof(decimal) || typ == typeof(float))
                                    { if (string.IsNullOrEmpty(user.Rows[j][k].ToString())) { dr[k] = "0"; } else { dr[k] = user.Rows[j][k].ToString(); } }
                                    else
                                    { if (string.IsNullOrEmpty(user.Rows[j][k].ToString())) { dr[k] = " "; } else { dr[k] = user.Rows[j][k].ToString(); } }
                                }
                                //dr["UserID"] = user.Rows[j][l].ToString();
                                //dr["UserName"] = user.Rows[j][l + 1].ToString();
                                //网dataset中添加数据
                                data.Tables[0].Rows.Add(dr);
                                //}
                            }
                            data.Tables[0].TableName = tablename;
                            i = adp.Update(data.Tables[0]);     //通过update方法Insert或update数据 
                            Console.WriteLine(i.ToString());
                        }
                    }
                }
            }
            //判断异常类型
            catch (SqlException er)
            {
                ErrorTime++;
                if (ErrorTime > 3)
                { FileLog.Logger.Write(er); FileLog.Logger.Write("错误次数太多，退出程序！"); Console.WriteLine("错误次数太多，退出程序！"); }
                else
                {
                    if (ErrorTime % 2 == 0)
                    {
                        FileLog.Logger.Write("尝试使用MSSQL身份验证登陆数据库！"); FileLog.Logger.Write(er); Console.WriteLine("SQLSERVER打开失败，尝试使用MSSQL方式登录数据库。");
                        string sqlcon = string.Format("Data Source={0};Initial Catalog={1};User ID={2};Password={3}", ConfigHelper.DBHost, "mpcy", ConfigHelper.DBName, ConfigHelper.DBPwd);
                        //string sqlcon = string.Format("Data Source={0};Initial Catalog={1};User ID={2};Password={3}", "127.0.0.1", "mpcyTemp", "sa", "12345");
                        BackupA("", state, sqlcon);
                    }
                    else
                    { FileLog.Logger.Write("尝试使用WINDOWS身份验证登陆数据库！"); FileLog.Logger.Write(er); Console.WriteLine("SQLSERVER打开失败，尝试使用WINDOWS方式登录数据库。"); BackupA("", state); }
                }
            }
            catch (Exception e)
            {
                FileLog.Logger.Write("数据导出失败！"); FileLog.Logger.Write(e); Console.WriteLine("数据导出失败！");
                //throw (new Exception("数据导出失败,请联系IT部！"));
            }
            finally
            {
                conn.Close();
            }
            if (state == 0)
            {
                string sqlcon = string.Format("Data Source={0};Initial Catalog={1};User ID={2};Password={3}", ConfigHelper.DBHost, "mpcyTemp", ConfigHelper.DBName, ConfigHelper.DBPwd);
                //string sqlcon = string.Format("Data Source={0};Initial Catalog={1};User ID={2};Password={3}", "127.0.0.1", "mpcyTemp", "sa", "12345");
                BackupA("", 1, sqlcon);
            }
        }

        /// <summary>
        /// 检查并备份
        /// </summary>
        /// <param name="check"></param>
        /// <param name="root"></param>
        static void chkandcrt(string root)
        {
            try { if (!Directory.Exists(BakPath)) { Directory.CreateDirectory(BakPath); } if (!File.Exists(BakPath + "\mpcy.dat")) { File.Copy(root, BakPath + "\mpcy.dat"); } }
            catch (Exception e)
            { FileLog.Logger.Write(e); FileLog.Logger.Write("文件检查失败！"); Console.WriteLine("文件信息检查失败！"); }
        }

代码不多，核心代码就这几句：

OleDbDataAdapter adp = new OleDbDataAdapter(); adp.SelectCommand = new OleDbCommand(string.Format("select * from {0}", tablename), conn); OleDbCommandBuilder cb = new OleDbCommandBuilder(adp); DataSet data = new DataSet();
 44                             //加载access中的数据表，并通过追加的方式放入dataset中
 45                             adp.Fill(data);
 46                             for (int j = 0; j < user.Rows.Count; j++)
 47                             {
 48                                 //for (int l = 0; l < user.Columns.Count; l++)
 49                                 //{
 50                                 //    if (l > user.Columns.Count - 1)
 51                                 //        break;
 52                                 DataRow dr = data.Tables[0].NewRow();
 53                                 for (int k = 0; k < dr.Table.Columns.Count; k++)
 54                                 {
 55                                     Type typ = user.Rows[j][k].GetType();
 56                                     if (typ == typeof(double) || typ == typeof(int) || typ == typeof(decimal) || typ == typeof(float))
 57                                     { if (string.IsNullOrEmpty(user.Rows[j][k].ToString())) { dr[k] = "0"; } else { dr[k] = user.Rows[j][k].ToString(); } }
 58                                     else
 59                                     { if (string.IsNullOrEmpty(user.Rows[j][k].ToString())) { dr[k] = " "; } else { dr[k] = user.Rows[j][k].ToString(); } }
 60                                 }
 61                                 //dr["UserID"] = user.Rows[j][l].ToString();
 62                                 //dr["UserName"] = user.Rows[j][l + 1].ToString();
 63                                 //网dataset中添加数据
 64                                 data.Tables[0].Rows.Add(dr);
 65                                 //}
 66                             }
 67                             data.Tables[0].TableName = tablename;
 68                             i = adp.Update(data.Tables[0]);     //通过update方法Insert或update数据 
 69                             Console.WriteLine(i.ToString());

这中间是这样的：先通过一个DataAdapter读取了Access数据库的结构，然后再通过从Sqlserver中读取到数据的DataTable将数据导入到这个被DataAdapter填充了结构的DataSet的表中。最后，通过这个DataAdapter来更新整个表，当然，表的结构要一致！！

另外，这里有一个OleDbCommandBuilder，根据网上解释:自动生成用于协调对 DataSet的更改与关联数据库的单表命令。也就是说，在我们这个例子中，我们的表结构是没有改变，但是后面新添加了数据，于是这个OleDbCommandBuilder就会自动将表单命令生成为Insert语句，于是就执行了插入命令，但是如果在我们初始化的DataSet中本来就存在数据，然后我们进行了对原始数据的改变，后面就会将命令变成Update。

这样，就将Sqlserver中的数据填充到了Access数据库中了。

参考：http://bbs.bccn.net/thread-292655-1-1.html

http://blog.csdn.net/a3676212/article/details/2776027

http://www.cnblogs.com/rhythmK/archive/2010/07/19/1780874.html