如何以编程方式备份 SQL Server 2014 Express Localdb (.mdf) 文件

本文关键字：Localdb Express mdf 文件 2014 Server 编程 方式 SQL 备份 | 更新日期: 2023-09-27 18:37:22

我有一个简单的Windows应用程序，它使用SQL Server 2014 LocalDB（.mdf文件）。

我希望每当用户单击退出按钮时，我的应用程序都会自动将其localdb文件（.mdf）备份到用户同一台计算机中的另一个文件夹中。

我在下面写了简单的代码，但发生了SQLException语法错误：

"C：''greendb_angelheart.mdf"附近的语法不正确

（DATABASE ""{0}""语法似乎很好）

我担心使用普通SqlConnection代码连接到特定的localdb文件是否正确。

我的简单代码是：

private void Window_Closing(object sender, System.ComponentModel.CancelEventArgs e)
{
    if (MessageBox.Show("Really want to exit? Thank you !", MessageBoxButton.YesNo, MessageBoxImage.Warning) == MessageBoxResult.No)
    {
            e.Cancel = true;
    }
    else
    {
            string backuppath_basic = @"c:'Green_Backup";
            if (!System.IO.Directory.Exists("backuppath_basic"))
            {
                System.IO.Directory.CreateDirectory(backuppath_basic);
            }
            var greendbfileName = System.IO.Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData), string.Format("greendb_{0}.mdf", personID));
            var copied_greendbfileName = string.Format(@"C:'greendb_{0}.mdf", personID);
            string localConnectionString = string.Format(@"Data Source=(LocalDB)'MSSQLLocalDB;AttachDbFilename= " + Environment.GetEnvironmentVariable("APPDATA") + @"'greendb_{0}.mdf;Integrated Security=True;Connect Timeout=30;", personID);
            SqlConnection backupConn = new SqlConnection();
            backupConn.ConnectionString = localConnectionString;
            backupConn.Open();
            SqlCommand backupcomm = backupConn.CreateCommand();
            string backupdb = @"BACKUP DATABASE ""{0}"" TO DISK '{1}'";
            backupdb = string.Format(backupdb, greendbfileName, copied_greendbfileName);
            SqlCommand backupcreatecomm = new SqlCommand(backupdb, backupConn);
            backupcreatecomm.ExecuteNonQuery();
            backupConn.Close();
            Environment.Exit(0);
        }
    }

如何以编程方式备份 SQL Server 2014 Express Localdb (.mdf) 文件

它可能会帮助某人。

备份

try
{
    var dlg = new System.Windows.Forms.FolderBrowserDialog();
    var result = dlg.ShowDialog(this.GetIWin32Window());
    if (result.ToString() == "OK")
    {
        var dbfileName = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData), "LibraryManger.mdf");
        var backupConn = new SqlConnection { ConnectionString = eb.GetConnectionString() };
        backupConn.Open();
        var backupcomm = backupConn.CreateCommand();
        var backupdb = $@"BACKUP DATABASE ""{dbfileName}"" TO DISK='{Path.Combine(dlg.SelectedPath,"LibraryManagement.bak")}'";
        var backupcreatecomm = new SqlCommand(backupdb, backupConn);
        backupcreatecomm.ExecuteNonQuery();
        backupConn.Close();
        MessageBox.Show($"Database backup has successfully stored in {Path.Combine(dlg.SelectedPath, "LibraryManagement.bak")}", "Confirmation");
    }
}
catch (Exception ex)
{
    if(ex.Message.Contains("Operating system error"))
    {
        MessageBox.Show("Please chose a public folder.", "Error", MessageBoxButton.OK, MessageBoxImage.Error);
    }
    else
        MessageBox.Show(ex.Message, "Error", MessageBoxButton.OK, MessageBoxImage.Error);
}

恢复

在

还原之前，必须关闭现有连接

try
{
    if (eb != null)
    {
        eb.DisposeConnection();
        eb = null;
    }
    var dlg = new OpenFileDialog();
    dlg.InitialDirectory = "C:''";
    dlg.Filter = "Database file (*.bak)|*.bak";
    dlg.RestoreDirectory = true;
    if (Equals(dlg.ShowDialog(), true))
    {
        using (var con = new SqlConnection())
        {
            con.ConnectionString = @"Data Source=(LocalDB)'MSSQLLocalDB;Database=Master;Integrated Security=True;Connect Timeout=30;";
            con.Open();
            var dbfileName = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData), "LibraryManger.mdf");
                using (var cmd = new SqlCommand())
                {
                    cmd.Connection = con;
                    cmd.CommandText = $@"RESTORE DATABASE ""{dbfileName}"" FROM DISK='{dlg.FileName}'";
                    cmd.ExecuteNonQuery();
                }
                con.Close();
            }
        MessageBox.Show($"Database backup has successfully restored.", "Confirmation");
        eb = new EntityBroker.EntityBroker();
    }
}
catch (Exception ex)
{
    MessageBox.Show(ex.Message, "Error", MessageBoxButton.OK, MessageBoxImage.Error);
}

经过多次试验和分析，我终于解决了。对于正在寻找解决方案的人，我分享我的解决方案如下。

似乎使用MS SQL Localdb开发的人比其他数据库少。

数据库的名称不必像 .mdf 那样包含扩展名，等号 = 必须一起作为 DISK=

字符串备份数据库 = 字符串。格式（@"备份数据库greendb_{0}到磁盘='c：''Green_Backup''greendb_{0}.bak'"， personID）;

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