How to do DB backup with VistaDB? - vb.net

Question

I'm trying to do a XML export of the database with VistaDB.
Unfortuanently, I'm lost.
Here's my code so far:
Dim instance As IVistaDBDatabase
Dim value As System.Int64
SaveFileDialog2.InitialDirectory = "C:\"
Select Case SaveFileDialog2.ShowDialog()
Case Windows.Forms.DialogResult.OK
Try
instance.ExportXml(SaveFileDialog2.FileName, VistaDBXmlWriteMode.All)
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End Select
All I get is object not set to instance of an object (or something like that).
Can anyone provide so guidance?

Answer 1

I was able to figure it out with help from an old code package.
Here is the proper code:
Dim vdbDatabase As IVistaDBDatabase = Nothing
Dim filenameDB As String = SaveFileDialog2.FileName
Dim filenameXML As String = SaveFileDialog2.FileName
Select Case SaveFileDialog2.ShowDialog()
Case System.Windows.Forms.DialogResult.OK
Try
' Call the method that will open the connection to the database and return an open IVistaDBDatabase object for the database to us
vdbDatabase = DDA.VistaDBEngine.Connections.OpenDDA.OpenDatabase("C:\Ledger.vdb5", VistaDBDatabaseOpenMode.NonexclusiveReadOnly, Nothing)
' Clear the XML Transfer List - this is the list used by the Import/Export methods
vdbDatabase.ClearXmlTransferList()
' Loop through the tables in the database and add them to the XmlTransferList
For Each tableName As String In vdbDatabase.GetTableNames()
vdbDatabase.AddToXmlTransferList(tableName)
Next
' Call the ExportXML method with the name of the XML file and the WriteMode value indicating what to Export
vdbDatabase.ExportXml(filenameXML, VistaDBXmlWriteMode.All)
' If the database is open - close it
If Not vdbDatabase.IsClosed Then
vdbDatabase.Close()
End If
MsgBox("Database Export complete.", MsgBoxStyle.Information)
Catch ex As Exception
WriteErrorEvent("Error exporting Database in addin", ex)
MsgBox("An error occured attempting to export the Database. Error Message:" & vbCrLf & vbCrLf & ex.ToString, MsgBoxStyle.Exclamation)
Finally
' If we have a vdbDatabase object
If Not (vdbDatabase Is Nothing) Then
' If it is open, close it
If Not vdbDatabase.IsClosed Then
vdbDatabase.Close()
End If
' Dispose of the object
vdbDatabase.Dispose()
End If
End Try
End Select

Answer 2

A Little late but i've made a small change to your code, so you can see the exact time of your backup.
Dim vdbDatabase As IVistaDBDatabase = Nothing
Dim filenamedb As String = vdbDatabase
Dim filenameXML As String = "MyDataBaseName_" + Now.ToString("dd-MM-yyyy_hh-mm-ss") + ".Xml"
Dim path As String
path = System.IO.Path.GetFullPath(filenameXML)
Try
vdbDatabase = DDA.VistaDBEngine.Connections.OpenDDA.OpenDatabase("DataDirectory|MyDataBase.vdb5", VistaDBDatabaseOpenMode.NonexclusiveReadOnly, Nothing)
vdbDatabase.ClearXmlTransferList()
For Each tableName As String In vdbDatabase.GetTableNames()
vdbDatabase.AddToXmlTransferList(tableName)
Next
vdbDatabase.ExportXml(filenameXML, VistaDBXmlWriteMode.All)
If Not vdbDatabase.IsClosed Then
vdbDatabase.Close()
End If
MsgBox("Backup is in " + path, MsgBoxStyle.Information)
Catch ex As Exception
MsgBox("An error occured attempting to export the Database. Error Message:" & vbCrLf & vbCrLf & ex.ToString, MsgBoxStyle.Exclamation)
Finally
If Not (vdbDatabase Is Nothing) Then
If Not vdbDatabase.IsClosed Then
vdbDatabase.Close()
End If
vdbDatabase.Dispose()
End If
End Try