主题：自动更新数据库

 

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点击浏览该文件:同步表结构_例子3.table

存在相同名字的表，但是目标数据库的表没有原数据表的列，想增加同名同类型的，我在例子中添加了相关代码，一直提示错误，问题在那里，该怎么修改呀？

 Else
                If DataTables.Contains(tname) Then DataTables.Unload(tname)
                Dim Builder As New ADOXBuilder("temp")
                Builder.Open() '打开ADOXBuilder
                msgbox(tname)
                Dim tbl2 As ADOXTable = Builder.Tables(tname)
                'For Each dc As DataCol In DataTables(tname).DataCols
                'Dim DcDatatype As object
                'If dc.IsBoolean Then
                'DcDatatype = ADOXType. Boolean
                'tbl2.AddColumn(dc.name,DcDatatype)
                'ElseIf dc.IsDate Then
                'DcDatatype = ADOXType. DateTime
                'tbl2.AddColumn(dc.name,DcDatatype)
                'ElseIf dc.IsNumeric Then
                'If dc.datatype.Name = "Double" Then
                'DcDatatype = ADOXType.Double
                'ElseIf dc.datatype.Name = "Decimal"
                'DcDatatype = ADOXType.Decimal
                'End If
                'tbl2.AddColumn(dc.name,DcDatatype)
                'ElseIf dc.IsString Then
                'DcDatatype = ADOXType.String
                'tbl2.AddColumn(dc.name,DcDatatype,dc.MaxLength)
                'End If
                'Next
                'Builder.Close()

以上代码在执行到For Each dc As DataCol In DataTables(tname).DataCols时发生错误

更新数据库表的代码如下：

Dim dlg As new OpenFileDialog
dlg.InitialDirectory = ProjectPath
dlg.Filter = "Access文件|*.mdb"
If dlg.ShowDialog = DialogResult.OK Then
    msgbox("本例子只处理一种情况->没有的表动态新增")
    '默认同步项目目录下的 test03 test05 两个数据库
    Dim mdbs() As String = {"tea01.mdb","tea02.mdb","tea04.mdb"}
    If Connections.Contains("test") Then Connections.Delete("test")
    Connections.Add("test", "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & dlg.FileName & ";Persist Security Info=False")
    For Each mdb As String In mdbs
        If Connections.Contains("temp") Then Connections.Delete("temp")
        Connections.Add("temp", "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & ProjectPath & mdb & ";Persist Security Info=False")
        Dim tnames As List(Of String) = Connections("temp").GetTableNames
        For Each tname As String In Connections("test").GetTableNames
            msgbox(tname)
            If tnames.Contains(tname) = True Then '如果此表没有,就动态新增
msgbox(tnames.Contains(tname))
                If DataTables.Contains(tname) Then DataTables.Unload(tname)
                'Dim q As new OuterTableBuilder
                'q.TableName = tname
                'q.C
                'q.SelectString = "Select * Fr om {" & tname & "} Where 1=2"
                'q.Build
                Dim Builder As New ADOXBuilder("temp") '要指定数据源名称
                Dim tbl As ADOXTable
                Builder.Open()
                tbl = Builder.Tables(tname) '创建表
msgbox(1)
                For Each dc As DataCol In DataTables(tname).DataCols
                    Dim DcDatatype As object
                    If dc.IsBoolean Then
                        DcDatatype = ADOXType. Boolean
                        tbl.AddColumn(dc.name,DcDatatype)
                    ElseIf dc.IsDate Then
                        DcDatatype = ADOXType. DateTime
                        tbl.AddColumn(dc.name,DcDatatype)
                    ElseIf dc.IsNumeric Then
                        If dc.datatype.Name = "Double" Then
                            DcDatatype = ADOXType.Double
                        ElseIf dc.datatype.Name = "Decimal"
                            DcDatatype = ADOXType.Decimal
                        End If
                        tbl.AddColumn(dc.name,DcDatatype)
                    ElseIf dc.IsString Then
                        DcDatatype = ADOXType.String
                        tbl.AddColumn(dc.name,DcDatatype,dc.MaxLength)
                    End If
                Next
                Builder.AddTable(tbl, True, True) '增加表
                Builder.Close()
                msgbox(mdb & "新增【" & tname & "】表成功")
            End If
        Next
    Next
End If

自己看懂代码啊，我测试没问题啊。

你的代码是增加表，我的代码是想在表存在的情况下，如果没有相应的列则增加相应的列

 看21楼啊。

比如test01、test02都有表A，但是test01表中有姓名列、test02没有姓名列，想通过代码让test02也按test01的格式增加姓名列？

哦，上传错了项目

 

 

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点击浏览该文件:同步表结构_例子3.table