部署项目后如何在winform C#中备份和恢复mdf文件？

Question

我正在 c# Visual Studio 2013 中开发一个桌面应用程序，我想在其中创建一个允许用户自行恢复和备份数据库的功能。但问题是部署项目后它不会备份或恢复数据库。

当我尝试备份时，它说！

数据库“DatabaseName”没有退出。请确保输入的名称正确。 BACKUP DATABASE 异常终止。

当我尝试恢复数据库时，它说

System.Data.Sqlclient.SqlException (0x80131904): 用户无权更改数据库.mdf'，数据库不退出，或数据库未处于允许访问检查的状态。等等！

我通过将 mdf 文件附加到应用程序来使用 SQL Server Express 2012，当我尝试使用查询进行备份时，当我通过 SQL Server 添加连接字符串时它可以工作，但在附加 mdf 文件后我将无法工作。

看过一些教程视频并想出了一些代码，但我什么也没得到

这是我的备份代码！

private void buttonbackup_Click(object sender, EventArgs e)
{
    try
    {

         SqlConnection con = new SqlConnection(@"Data Source=(LocalDB)\v11.0;AttachDbFilename=|DataDirectory|\neyadatabase.mdf;Integrated Security=True;Connect Timeout=30");
         con.Open();

         String sql = "BACKUP DATABASE neyadatabase TO DISK = '" + backuploca.Text + "\\neyadatabase - " + DateTime.Now.Ticks.ToString() + ".Bak'";
          SqlCommand cmd = new SqlCommand(sql, con);
          cmd.ExecuteNonQuery();
          MessageBox.Show("backup done successfully!");
          con.Close();
          con.Dispose();
      }

      catch (Exception ex)
      {
          MessageBox.Show(ex.Message);
      }  
}

这是我的恢复代码！

private void buttonrestore_Click(object sender, EventArgs e)
{

    try
    {

         SqlConnection con = new SqlConnection(@"Data Source=(LocalDB)\v11.0;AttachDbFilename=|DataDirectory|\neyadatabase.mdf;Integrated Security=True;Connect Timeout=30");
         con.Open();
         string sqlStmt2 = string.Format("ALTER DATABASE [neyadatabase.mdf] SET SINGLE_USER WITH ROLLBACK IMMEDIATE");
         SqlCommand bu2 = new SqlCommand(sqlStmt2, con);
         bu2.ExecuteNonQuery();

         string sqlStmt3 = "USE MASTER RESTORE DATABASE [neyadatabase.mdf] FROM DISK='" + restoreloca.Text + "'WITH REPLACE;";
         SqlCommand bu3 = new SqlCommand(sqlStmt3, con);
         bu3.ExecuteNonQuery();

         string sqlStmt4 = string.Format("ALTER DATABASE [neyadatabase.mdf] SET MULTI_USER");
         SqlCommand bu4 = new SqlCommand(sqlStmt4, con);
         bu4.ExecuteNonQuery();

         MessageBox.Show("database restoration done successefully");
         con.Close();

      }
      catch (Exception ex)
      {
         MessageBox.Show(ex.ToString());
      }


}

我是这方面的初学者，如果有人要帮助我，请也举一些例子，以便我更好地理解！

谢谢

Answer 1

用于备份：

private void buttonbackup_Click(object sender, EventArgs e)
{
    try
    {
        using (SqlConnection dbConn = new SqlConnection())
        {
             dbConn.ConnectionString = @"Data Source=(LocalDB)\MSSQLLocalDB;Database=neyadatabase;Integrated Security=True;Connect Timeout=30;";
             dbConn.Open();

             using (SqlCommand multiuser_rollback_dbcomm = new SqlCommand())
             {
                 multiuser_rollback_dbcomm.Connection = dbConn;
                 multiuser_rollback_dbcomm.CommandText= @"ALTER DATABASE neyadatabase SET MULTI_USER WITH ROLLBACK IMMEDIATE";

                 multiuser_rollback_dbcomm.ExecuteNonQuery();
             }
             dbConn.Close();
        }

        SqlConnection.ClearAllPools();

        using (SqlConnection backupConn = new SqlConnection())
        {
            backupConn.ConnectionString = yourConnectionString;
            backupConn.Open();

            using (SqlCommand backupcomm = new SqlCommand())
            {
                backupcomm.Connection = backupConn;
                backupcomm.CommandText= @"BACKUP DATABASE neyadatabase TO DISK='c:\neyadatabase.bak'";
                backupcomm.ExecuteNonQuery();
            }
            backupConn.Close();
        }
    }

    catch (Exception ex)
    {
        MessageBox.Show(ex.Message);
    }  
}

对于恢复：

private void buttonrestore_Click(object sender, EventArgs e)
{
    try
    {
        using (SqlConnection restoreConn = new SqlConnection())
        {
            restoreConn.ConnectionString = @"Data Source=(LocalDB)\MSSQLLocalDB;Database=neyadatabase;Integrated Security=True;Connect Timeout=30;";
            restoreConn.Open();
            using (SqlCommand restoredb_executioncomm = new SqlCommand())
            {
                restoredb_executioncomm.Connection = restoreConn;
                restoredb_executioncomm.CommandText = @"RESTORE DATABASE neyadatabase FROM DISK='c:\neyadatabase.bak'";

                restoredb_executioncomm.ExecuteNonQuery();
            }
            restoreConn.Close();
        }
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.ToString());
    }
}

• 备份和恢复bak 文件。 Mdf/ldf 用于附加而非备份。

我希望这对你有帮助。 如果您遇到任何问题，请告诉我以更新我的答案；）。祝你好运