by Newsgroup Posting (15 Submissions)
Category: Databases/Data Access/DAO/ADO
Compatability: Visual Basic 3.0
Difficulty: Unknown Difficulty
Date Added: Wed 3rd February 2021
Rating: 
(4 Votes)
A short routine that backups the tables from an open Access database
George Kinney
Assumes
Right now it is basic, it assumes that the tables to backup are in the
local database (easily changed, just haven't had a chance to do it.),
and just exports EVERYTHING that isn't filtered out.
A number of improvements can (and will eventually) be built in so that it
can address attached tables, multiple backups, backup logging, etc. These
are all things I need to add anyways for a current project, and when they
are done, I'll b eposting them to.
Apologies are in order to a few of the people I sent code. The function
relied on a couple of outside functions, not included in the post, and
also contained a lot extraneous junk (you who work with large projects full
time know how this stuff accumulates, those who don't, well you'll find
out.). To these people, I'm sorry for that, and hope you don't take me to
be a complete idiot. (3am is a bad time to reply to mail!)
I don't claim to be a programming guru, but I think this example could
benefit some people. I recieved a lot of help from others early on, so I
intend to give what I can as I can so others can hopefully benefit from me.
'Just call BackupDatabase() with the name of the backup file
'you want to create, and sit back.
API DeclarationsConst modulename = "MBackup"
VBcodersFunction BackupDataBase (filename$) As Integer
'**********************************************************************************
'* PROCEDURE: BackupDataBase
'* ARGS: filename$ -- name of new DataBase, defaults to current Dir
'* RETURNS: TRUE/FALSE
'* CREATED: 7/95
'* REVISED: 8/2/95 GDK Changed to use the App's dir.
'* Comments Creates newDataBase, and exports ALL existing tables in the
'* Current database to it.
'* ToDo: Backup current backup before writing over it. (part of backup
'* archive system)
'* Add new backup logging stuff to this function.(Date, location, etc.)
'**********************************************************************************
On Error GoTo BackupDataBase_Err
Dim newDB As Database, oldDB As Database, oldTable As TableDef
Dim tempname As String, path As String, intIndex As Integer, numTables As Integer
Dim intIndex2 As Integer, errorFlag As Integer
'backup defaults to current directory,...
path = GetApplicationDir() & filename$
'replace above line with this one to pass a full path to this function
'path = filename$
'If database already exists, delete it.
If MB_FileExists(path) Then
Kill path
End If
'create new file
Set newDB = DBEngine.workspaces(0).CreateDatabase(path, DB_LANG_GENERAL)
newDB.Close
Set oldDB = DBEngine(0)(0)
'Get number of tables and their names
numTables = oldDB.tabledefs.count - 1
'Actually export all the tables in the list.
For intIndex = 0 To numTables
tempname = oldDB.tabledefs(intIndex).name
If ValidTableFilter(tempname) Then
DoCmd TransferDatabase A_EXPORT, "Microsoft Access", path, A_TABLE, tempname, tempname
End If
Next intIndex
BackupDataBase = True
BackupDataBase_Exit:
If errorFlag Then
BackupDataBase = False
'if we errored out, then destroy the backup, (less risk of using incorrect file).
If MB_FileExists(path) Then
Kill path
End If
Else
BackupDataBase = True
End If
Exit Function
BackupDataBase_Err:
MsgBox "Backup Failed! Error: " & Error$, 16, "FUNCTION: BackupDataBase( " & filename$ & " )"
errorFlag = True
Resume BackupDataBase_Exit
End Function
Function GetApplicationDir () As String
'***************************************************************************
'* PROCEDURE: GetApplicationDir
'* ARGS: NONE
'* RETURNS: App's dir
'* CREATED: 8/2/95 GDK
'* REVISED:
'* Comments Retrieves App's directory, (actually the current MDB's dir.)
'***************************************************************************
Dim d As Database, path As String, i%
Set d = DBEngine(0)(0)
path = d.name
d.Close
For i% = Len(path) To 0 Step -1
If Mid$(path, i%, 1) = "\" Then
path = Left$(path, i%)
Exit For
End If
Next i%
GetApplicationDir = path
End Function
'*************************************************************
'* FUNCTION: MB_FileExists
'* ARGUMENTS: strFilename -- name of file to look for
'* RETURNS: TRUE/FALSE -- TRUE = File Exists
'* CREATED: 8/95 GDK Initial Code
'* CHANGED: N/A
'*************************************************************
Function MB_FileExists (strFileName As String) As Integer
'
'Check to see if file strFileName exists
'
If Len(Dir$(strFileName)) Then
MB_FileExists = True
End If
End Function
'***************************************************************
'* FUNCTION: ValidTableFilter
'* ARGUMENTS: tablename$ -- table to OK for export
'* RETURNS: TRUE/FALSE -- TRUE = OK to export
'* PURPOSE: Screen out invalid tables by testing them here.
'* CREATED: 2/97 GDK Initial code
'* CHANGES: N/A
'***************************************************************
Function ValidTableFilter (tablename$) As Integer
On Error GoTo ValidTableFilter_Error:
If Left$(tablename$, 4) = "MSys" Then
Exit Function
End If
If tablename$ = "" Then
Exit Function
End If
'Add test functions above this line.
ValidTableFilter = True
ValidTableFilter_Exit:
Exit Function
ValidTableFilter_Error:
MsgBox Error, 16, "FUNCTION: ValidTableFilter( " & tablename$ & ")"
Resume ValidTableFilter_Exit
End Function
