Posts tagged ‘Access’

Verlinkte Access Datenbanken umziehen lassen

Ich muss gelegentlich eine Access-Datenbank umziehen lassen, die auf diverse verlinkte Datenbanken zugreift (um das 2 GB Maximum zu umgehen). Da die Verlinkungen absolut sind und nicht relativ, muss man jede Verlinkung nach dem Umzug manuell anpassen, was bei mehr als 100 Tabellen mühselig und fehlerträchtig ist. Basierend auf Code von Stackexchange/Stackoverflow habe ich daher ein paar Hilfsfunktionen gebaut, die den Umzug deutlich vereinfachen. Die Annahme

Der Code besteht aus mehreren Funktionen:

  • getDatabaseName() extrahiert den Namen der Datenbank aus dem Pfad
  • GetFolder()
  • fragt beim Nutzer den Pfad ab, in dem die neuen Datenbank-Dateien liegen.

  • verlinkeTabellenNeu() biegt die Links auf die Datenbankdateien um

Hinweis: Es empfiehlt sich nach Abschluss ein Auslesen aller Verlinkungen und Abgleichen z.B. in Excel, um auf Nummer sicher gehen zu können, dass alle Verlinkungen erfolgreich waren. Zum Auslesen der Verlinkungen kann man den Code unten am Ende des Artikels nutzen.

Option Compare Database
 
Function getDatabaseName(currentPath As String)
    ' Uwe Ziegenhagen, 2017-11-03
    ' Extrahiert den Namen der Datenbank aus dem Pfad,
    ' wertet dazu die Position des letzten "\" aus:
    ' von innen nach außen:
    ' kehre String um
    ' finde den letzten Backslash
    ' nimm den substring bis zum letzten Backslash
    ' reverse diesen Substring wieder
 
getDatabaseName = StrReverse(Left(StrReverse(currentPath), InStr(StrReverse(currentPath), "\") - 1))
 
End Function
 
Function GetFolder() As String
' https://stackoverflow.com/questions/26392482/vba-excel-to-prompt-user-response-to-select-folder-and-return-the-path-as-string
' based on https://www.ozgrid.com/forum/forum/help-forums/excel-general/126180-getfolder-function?t=182343
 
' requires references to Microsoft Office xx.0 Object library
    Dim fldr As FileDialog
    Dim sItem As String
    Set fldr = Application.FileDialog(msoFileDialogFolderPicker)
    With fldr
        .Title = "Select a Folder"
        .AllowMultiSelect = False
        '.InitialFileName = Application.DefaultFilePath
        If .Show <> -1 Then GoTo NextCode
        sItem = .SelectedItems(1)
    End With
NextCode:
    GetFolder = sItem
    Set fldr = Nothing
End Function
 
Sub verlinkeTabellenNeu()
' Uwe Ziegenhagen, 2017-11-03
' Ruft vom User einen Pfad ab und verlinkt alle Tabellen mit diesem Pfad neu
' based on code from https://stackoverflow.com/questions/4928134/changing-linked-table-location-programatically
 
ordnerNeu = GetFolder()
Dim dbs As DAO.Database
Dim tdf As DAO.TableDef
Set dbs = CurrentDb()
 
    With dbs
        For Each tdf In .TableDefs
        'Is the table a linked table?
            If tdf.Attributes And dbAttachedODBC Or tdf.Attributes And dbAttachedTable Then
                With tdf
                    oldPath = .Properties("Connect").Value
                    .Connect = ";DATABASE=" & ordnerNeu & "\" & getDatabaseName(.Properties("Connect").Value)
                    .RefreshLink
                    Debug.Print oldPath & "@@@" & .Properties("Connect").Value
                End With
            End If
        Next tdf
    End With
 
End Sub

Code zum Auslesen der Verlinkungen

Sub LinkedTableConnection()
' http://p2p.wrox.com/access-vba/37117-finding-linked-tables.html
   Dim dbs As DAO.Database
   Dim tdf As DAO.TableDef
 
   Set dbs = CurrentDb()
 
    With dbs
        For Each tdf In .TableDefs
        'Is the table a linked table?
            If tdf.Attributes And dbAttachedODBC Or tdf.Attributes And dbAttachedTable Then
                With tdf
                    ' Connect property contains path of link
                    ' Debug.Print "Connect Property of " & .Name & " is: " &  .Properties("Connect").Value
                    Debug.Print "kompletter Pfad: " & tdf.Connect
                    ' Debug.Print "Name der Datenbank: " & getDatabaseName(.Properties("Connect").Value)
                End With
            End If
        Next tdf
    End With
End Sub

Uwe

Uwe Ziegenhagen likes LaTeX and Python, sometimes even combined. Do you like my content and would like to thank me for it? Consider making a small donation to my local fablab, the Dingfabrik Köln. Details on how to donate can be found here Spenden für die Dingfabrik.

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MS Access Tabellenstrukturen exportieren

Ich muss mich gelegentlich mit MS Access beschäftigen und habe eine Möglichkeit gesucht, Tabellenstrukturen zu exportieren. Basierend auf Code von Allen Browne (http://allenbrowne.com/func-06.html) habe ich um seine TableInfo() Funktion eine Exportfunktion geschrieben.

Option Compare Database
 
' based on http://allenbrowne.com/func-06.html
' modified for the export of the information by Uwe Ziegenhagen
 
Sub exportTableInformation()
On Error GoTo TableInfoErr
   ' Purpose:   Display the field names, types, sizes and descriptions for a table.
   ' Argument:  Name of a table in the current database.
   Dim db As DAO.Database
   Dim tdf As DAO.TableDef
   Dim fld As DAO.Field
 
   Set db = CurrentDb()
 
    ' ask user for path of the output file
    ' https://support.office.com/de-de/article/InputBox-Funktion-Eingabefeld-17821927-28b7-4350-b7f1-4786575314d9
    Dim Message, Title, Default, MyValue
    Message = "File will be overwritten..."   ' Set prompt.
    Title = "Enter file of output file"     ' Set title.
    Default = "c:\somefile.csv"               ' Set default.
    ' Display message, title, and default value.
    outputfilePath = InputBox(Message, Title, Default)
 
    n = FreeFile()
    Open outputfilePath For Output As #n
    Print #n, "SOURCE;TABLE;FIELDNAME;FIELDTYPE;SIZE;DESCRIPTION"
   Set db = CurrentDb()
 
    Debug.Print
 
    For Each tdf In db.TableDefs
        ' ignore system and temporary tables
        If Not (tdf.Name Like "MSys*" Or tdf.Name Like "~*") Then
            For Each fld In tdf.Fields
                Debug.Print db.Name & ";" & tdf.Name & ";" & fld.Name & ";" & FieldTypeName(fld) & ";" & fld.Size & ";" & GetDescrip(fld)
                Print #n, db.Name & ";" & tdf.Name & ";" & fld.Name & ";" & FieldTypeName(fld) & ";" & fld.Size & ";" & GetDescrip(fld)
            Next
        End If
    Next
 
    Set tdf = Nothing
    Set db = Nothing
 
    Close #n
 
TableInfoExit:
   Set db = Nothing
   Exit Sub
 
TableInfoErr:
   Select Case Err
   Case 3265&  'Table name invalid
      MsgBox strTableName & " table doesn't exist"
   Case Else
      Debug.Print "TableInfo() Error " & Err & ": " & Error
   End Select
   Resume TableInfoExit
End Sub
 
Function GetDescrip(obj As Object) As String
' http://allenbrowne.com/func-06.html
    On Error Resume Next
 
    GetDescrip = obj.Properties("Description")
 
End Function
 
 
 
Function FieldTypeName(fld As DAO.Field) As String
    'http://allenbrowne.com/func-06.html
    'Purpose: Converts the numeric results of DAO Field.Type to text.
    Dim strReturn As String    'Name to return
 
    Select Case CLng(fld.Type) 'fld.Type is Integer, but constants are Long.
        Case dbBoolean: strReturn = "Yes/No"            ' 1
        Case dbByte: strReturn = "Byte"                 ' 2
        Case dbInteger: strReturn = "Integer"           ' 3
        Case dbLong                                     ' 4
            If (fld.Attributes And dbAutoIncrField) = 0& Then
                strReturn = "Long Integer"
            Else
                strReturn = "AutoNumber"
            End If
        Case dbCurrency: strReturn = "Currency"         ' 5
        Case dbSingle: strReturn = "Single"             ' 6
        Case dbDouble: strReturn = "Double"             ' 7
        Case dbDate: strReturn = "Date/Time"            ' 8
        Case dbBinary: strReturn = "Binary"             ' 9 (no interface)
        Case dbText                                     '10
            If (fld.Attributes And dbFixedField) = 0& Then
                strReturn = "Text"
            Else
                strReturn = "Text (fixed width)"        '(no interface)
            End If
        Case dbLongBinary: strReturn = "OLE Object"     '11
        Case dbMemo                                     '12
            If (fld.Attributes And dbHyperlinkField) = 0& Then
                strReturn = "Memo"
            Else
                strReturn = "Hyperlink"
            End If
        Case dbGUID: strReturn = "GUID"                 '15
 
        'Attached tables only: cannot create these in JET.
        Case dbBigInt: strReturn = "Big Integer"        '16
        Case dbVarBinary: strReturn = "VarBinary"       '17
        Case dbChar: strReturn = "Char"                 '18
        Case dbNumeric: strReturn = "Numeric"           '19
        Case dbDecimal: strReturn = "Decimal"           '20
        Case dbFloat: strReturn = "Float"               '21
        Case dbTime: strReturn = "Time"                 '22
        Case dbTimeStamp: strReturn = "Time Stamp"      '23
 
        'Constants for complex types don't work prior to Access 2007 and later.
        Case 101&: strReturn = "Attachment"         'dbAttachment
        Case 102&: strReturn = "Complex Byte"       'dbComplexByte
        Case 103&: strReturn = "Complex Integer"    'dbComplexInteger
        Case 104&: strReturn = "Complex Long"       'dbComplexLong
        Case 105&: strReturn = "Complex Single"     'dbComplexSingle
        Case 106&: strReturn = "Complex Double"     'dbComplexDouble
        Case 107&: strReturn = "Complex GUID"       'dbComplexGUID
        Case 108&: strReturn = "Complex Decimal"    'dbComplexDecimal
        Case 109&: strReturn = "Complex Text"       'dbComplexText
        Case Else: strReturn = "Field type " & fld.Type & " unknown"
    End Select
 
 
    FieldTypeName = strReturn
 
End Function

Uwe

Uwe Ziegenhagen likes LaTeX and Python, sometimes even combined. Do you like my content and would like to thank me for it? Consider making a small donation to my local fablab, the Dingfabrik Köln. Details on how to donate can be found here Spenden für die Dingfabrik.

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