在 vb.net 中恢复 SQL Server localdb

Question

我想恢复一个 SQL Server localdb 数据库。我试过这段代码：

Private Sub Button4_Click(sender As Object, e As EventArgs) Handles Button4.Click
    Dim ofd As New OpenFileDialog() With
        {
            .Filter = "Backup file | *.bak",
            .FileName = ""
        }

    If ofd.ShowDialog = System.Windows.Forms.DialogResult.OK Then
            Cursor = Cursors.WaitCursor
            Dim csb = New SqlConnectionStringBuilder("Data Source=(LocalDB)\v11.0;AttachDbFilename=C:\Users\CHAKER\Documents\RestoDB.mdf;Integrated Security=True;Connect Timeout=30")
            Dim dbFullPath = csb.AttachDBFilename

            Dim sql = String.Format("RESTORE DATABASE ""{0}"" From DISK = '{1}'", dbFullPath, ofd.FileName)
            Dim cmd As New SqlCommand(sql, con)
            cmd.ExecuteNonQuery()
            MsgBox("Restore complete")
            Cursor = Cursors.Default

        End If

    End Sub

我得到了这个例外：

RESTORE 无法处理数据库“C:\Users\CHAKER\Documents\RestoDB.mdf”，因为该会话正在使用它。建议执行此操作时使用master数据库。

Answer 1

您的代码存在许多问题：

• 您的主要问题：您正在按文件名恢复数据库，但您已经使用AttachDbFileName 附加了它，并且无法恢复这样的数据库。 Using AttachDbFileName is in any case deprecated. 您应该使用普通的 CREATE DATABASE FOR ATTACH 语法将其附加到 LocalDB。
• 最好不要对连接字符串进行硬编码，而是将其存储在设置文件中。
• 您需要使用Using 处理您的连接和命令对象。不要缓存连接对象。
• 连接打开时不要使用 MessageBox 阻塞线程
• 您应该在RESTORE 命令上使用参数化，而不是直接注入名称

In settings file:
ConnectionString "Data Source=(LocalDB)\v11.0;Initial Catalog=RestoDB;Integrated Security=True;Connect Timeout=30"

Private Sub Button4_Click(sender As Object, e As EventArgs) Handles Button4.Click
    Dim ofd As New OpenFileDialog() With
        {
            .Filter = "Backup file | *.bak",
            .FileName = ""
        }

    If ofd.ShowDialog <> System.Windows.Forms.DialogResult.OK Then Exit Sub

    Try
        Cursor = Cursors.WaitCursor
        Const sql = "RESTORE DATABASE @DB From DISK = @FileName"
        Using con As New SqlConnection(Properties.ConnectionString),
              cmd As New SqlCommand(sql, con)
            cmd.Parameters.Add("@DB", SqlDbType.NVarChar, 128).Value = con.Database
            cmd.Parameters.Add("@FileName", SqlDbType.NVarChar, 255).Value = ofd.FileName
            cmd.ExecuteNonQuery()
        End Using
        MsgBox("Restore complete")
    Catch ex As Exception
        MsgBox("Error: " + ex.Message)
    Finally
        Cursor = Cursors.Default
    End Finally

End Sub