access下如何恢复已经删除的记录;如何恢复已经删除的表、窗体等等对象 |
问题: 如何 复原已经删除的记录;如何 复原已经删除的表、窗体等等对象 1、我用 DELETE FROM TABLE 删除了一些记录,现在发现误删除了,该如何 复原? 2、我直接手动删除或者用 DROP TABLE 删除了一个表,现在发现是误删除了,该如何 复原? 3、我手动删除了一个窗体,该如何 复原? 4、我删除了记录,可是数据库体积并没有减小,那么是不是能找回记录呢? 答复: 1、已经删除的记录是 无奈 复原的,ACCESS 不是 FOXPRO,MDB 格局不是 DBF 格局,没有逻辑删除和物理删除的概念,一旦删除就 无奈 复原了 。 2、 无奈 复原,然而你 可以查看一下,有没有 潜藏的以 "'" 符号开头的表,更改该表的名称有可能找回你需求的表 。 3、 无奈 复原,然而你 可以查看一下有没有系统 潜藏的对象,有时候对象被删除时系统并不直接删除,而是更改对象名后 潜藏它 。 4、数据库体积确实没有变小,你压缩修复数据库后体积就会变小了 。那是由于在二进制上你的数据确实没有被删除, 依旧 存放在磁盘的某个扇区,然而微软没有提供 MDB 格局二进制组织 模式的参考 材料(微软也不会提供, 其余第三方公司也没有 权力直接反编译 MDB 格局) 。至今为止,中国大陆我也没有看到过 有关的参考 材料 。所以当前为止,你已经删除的数据是 无奈 复原的 。然而你 可以尝试 使用磁盘 复原软件来找到 复原数据的 步骤,然而该 步骤不在本文 探讨 规模 。 提议:在 构建数据库 构造时, 可以在各个表中再多加一个 ISDEL 字段,删除记录时不 使用 DELETE FROM ,而 使用 UPDATE TABLE SET ISDEL=TRUE 这样的语句, 而后在界面上不显示 ISDEL=TRUE 的记录即可 。 复制代码 代码如下: 假如还没有被压缩 实际上 可以 。试试这段代码吧 。加在access模组中 恢復刪除的工作表(未被壓縮) Public Function FnUndeleteObjects() As Boolean On Error GoTo ErrorHandler: Dim strObjectName As String Dim rsTables As DAO.Recordset Dim dbsDatabase As DAO.Database Dim tDef As DAO.TableDef Dim qDef As DAO.QueryDef Dim intNumDeletedItemsFound As Integer Set dbsDatabase = CurrentDb For Each tDef In dbsDatabase.TableDefs This is actually used as a Deleted Flag If tDef.Attributes And dbHiddenObject Then strObjectName = FnGetDeletedTableNameByProp(tDef.Name) strObjectName = InputBox("A deleted TABLE has been found." & _ vbCrLf & vbCrLf & _ "To undelete this object, enter a new name:", _ "Access Undelete Table", strObjectName) If Len(strObjectName) > 0 Then FnUndeleteTable CurrentDb, tDef.Name, strObjectName End If intNumDeletedItemsFound = intNumDeletedItemsFound + 1 End If Next tDef For Each qDef In dbsDatabase.QueryDefs Note Attributes flag is not exposed for QueryDef objects, We could look up the flag by using MSysObjects but new queries dont get written to MSysObjects until Access is closed. Therefore well just check the start of the name is 'TMPCLP ... If InStr(1, qDef.Name, "'TMPCLP") = 1 Then strObjectName = "" strObjectName = InputBox("A deleted QUERY has been found." & _ vbCrLf & vbCrLf & _ "To undelete this object, enter a new name:", _ "Access Undelete Query", strObjectName) If Len(strObjectName) > 0 Then If FnUndeleteQuery(CurrentDb, qDef.Name, strObjectName) Then Well rename the deleted object since weve made a copy and wont be needing to re-undelete it. (To break the condition "'TMPCLP" in future...) qDef.Name = "'TMPCLQ" & Right$(qDef.Name, Len(qDef.Name) - 7) End If End If intNumDeletedItemsFound = intNumDeletedItemsFound + 1 End If Next qDef If intNumDeletedItemsFound = 0 Then MsgBox "Unable to find any deleted tables/queries to undelete!" End If Set dbsDatabase = Nothing FnUndeleteObjects = True ExitFunction: Exit Function ErrorHandler: MsgBox "Error occured in FnUndeleteObjects() - " & _ Err.Description & " (" & CStr(Err.Number) & ")" GoTo ExitFunction End Function Private Function FnUndeleteTable(dbDatabase As DAO.Database, _ strDeletedTableName As String, _ strNewTableName As String) Module (c) 2005 Wayne Phillips (http://www.everythingaccess.com) Written 18/04/2005 Dim tDef As DAO.TableDef Set tDef = dbDatabase.TableDefs(strDeletedTableName) Remove the Deleted Flag... tDef.Attributes = tDef.Attributes And Not dbHiddenObject Rename the deleted object to the original or new name... tDef.Name = strNewTableName dbDatabase.TableDefs.Refresh Application.RefreshDatabaseWindow Set tDef = Nothing End Function Private Function FnUndeleteQuery(dbDatabase As DAO.Database, _ strDeletedQueryName As String, _ strNewQueryName As String) Module (c) 2005 Wayne Phillips (http://www.everythingaccess.com) Written 18/04/2005 We cant just remove the Deleted flag on queries (Attributes is not an exposed property) So instead we create a new query with the SQL... Note: Cant use DoCmd.CopyObject as it copies the dbHiddenObject attribute! If FnCopyQuery(dbDatabase, strDeletedQueryName, strNewQueryName) Then FnUndeleteQuery = True Application.RefreshDatabaseWindow End If End Function Private Function FnCopyQuery(dbDatabase As DAO.Database, _ strSourceName As String, _ strDestinationName As String) Module (c) 2005 Wayne Phillips (http://www.everythingaccess.com) Written 18/04/2005 On Error GoTo ErrorHandler: Dim qDefOld As DAO.QueryDef Dim qDefNew As DAO.QueryDef Dim Field As DAO.Field Set qDefOld = dbDatabase.QueryDefs(strSourceName) Set qDefNew = dbDatabase.CreateQueryDef(strDestinationName, qDefOld.SQL) Copy root query properties... FnCopyLvProperties qDefNew, qDefOld.Properties, qDefNew.Properties For Each Field In qDefOld.Fields Copy each fields individual properties... FnCopyLvProperties qDefNew.Fields(Field.Name), _ Field.Properties, _ qDefNew.Fields(Field.Name).Properties Next Field dbDatabase.QueryDefs.Refresh FnCopyQuery = True ExitFunction: Set qDefNew = Nothing Set qDefOld = Nothing Exit Function ErrorHandler: MsgBox "Error re-creating query " & strDestinationName & ":" & vbCrLf & _ Err.Description & " (" & CStr(Err.Number) & ")" GoTo ExitFunction End Function Private Function PropExists(Props As DAO.Properties, strPropName As String) As Boolean Module (c) 2005 Wayne Phillips (http://www.everythingaccess.com) Written 18/04/2005 If properties fail to be created, well just ignore the errors On Error Resume Next Dim Prop As DAO.Property For Each Prop In Props If Prop.Name = strPropName Then PropExists = True Exit Function Short circuit End If Next Prop PropExists = False End Function Private Sub FnCopyLvProperties(objObject As Object, OldProps As DAO.Properties, NewProps As DAO.Properties) Module (c) 2005 Wayne Phillips (http://www.everythingaccess.com) Written 18/04/2005 If properties fail to be created, well just ignore the errors On Error Resume Next Dim Prop As DAO.Property Dim NewProp As DAO.Property For Each Prop In OldProps If Not PropExists(NewProps, Prop.Name) Then If IsNumeric(Prop.Value) Then NewProps.Append objObject.CreateProperty(Prop.Name, Prop.Type, CLng(Prop.Value)) Else NewProps.Append objObject.CreateProperty(Prop.Name, Prop.Type, Prop.Value) End If Else With NewProps(Prop.Name) .Type = Prop.Type .Value = Prop.Value End With End If Next Prop End Sub Private Function FnGetDeletedTableNameByProp(strRealTableName As String) As String Module (c) 2005 Wayne Phillips (http://www.everythingaccess.com) Written 18/04/2005 If an error occurs here, just ignore (user will override the blank name) On Error Resume Next Dim i As Long Dim strNameMap As String Look up the Unicode translation NameMap property to try to guess the original table name... (Access 2000+ only - and doesnt always exist?!) strNameMap = CurrentDb.TableDefs(strRealTableName).Properties("NameMap") strNameMap = Mid(strNameMap, 23) Offset of the table name... Find the null terminator... i = 1 If Len(strNameMap) > 0 Then While (i < Len(strNameMap)) And (Asc(Mid(strNameMap, i)) <> 0) i = i + 1 Wend End If FnGetDeletedTableNameByProp = Left(strNameMap, i - 1) End Function |