Question

我是更新数据库的新手，显然我并不擅长。

详细信息：

我使用tableadapter（我不知道这是否是最好的方法）在.mdf文件中引用我的数据库
我的表有两列，第一列是Primary Key
该表已有一些行
我在tableadapter中填写：Me.CCListTableAdapter.Fill(Me.HQSdbDataSet.CCList)

我正在尝试做什么：

我根据CCListTable创建了一个新的数据表：Dim ccDataTable As CCListDataTable = New CCListDataTable
我使用CsvReader将带有新行（> 3000行）的.csv文件导入到这个新数据表中。我的数据库中已存在行
然后我尝试将这些新行添加到tableadapter中：

Me.CCListBindingSource.EndEdit() Me.CCListTableAdapter.Update(ccDataTable)

但是它不起作用我得SqlException Violation of PRIMARY KEY [...] Cannot insert duplicate key。好的，就像我说我知道有重复的键，但我不想插入这些，但只更新tableadapter与新行。

这是我创建的用于导入CSV的子代码（如果可以帮助的话）：

Public Sub ImportCSV2Data(ByVal filename As String, ByRef datatable As DataTable, ByVal column2Import() As Integer,
                          ByVal tableAlreadyExist As Boolean)

    Dim csvCopy As CachedCsvReader = New CachedCsvReader(New StreamReader(filename), True, ";"c)
    csvCopy.MissingFieldAction = MissingFieldAction.ReplaceByEmpty

    Dim headers() As String = csvCopy.GetFieldHeaders
    If column2Import.Length > 0 AndAlso column2Import(0) > -1 Then
        If tableAlreadyExist Then
            While csvCopy.ReadNextRecord()
                Dim csvRow As DataRow = datatable.NewRow
                Dim i As Integer = 0
                For Each column As Integer In column2Import
                    Select Case datatable.Columns(i).DataType.Name
                        Case "String"
                            If String.IsNullOrEmpty(csvCopy(column)) Then
                                csvRow(i) = ""
                            Else
                                csvRow(i) = Convert.ToString(csvCopy(column))
                            End If
                        Case "Int32"
                            If String.IsNullOrEmpty(csvCopy(column)) Then
                                csvRow(i) = DBNull.Value
                            Else
                                csvRow(i) = Convert.ToInt32(csvCopy(column))
                            End If
                        Case "Double"
                            If String.IsNullOrEmpty(csvCopy(column)) Then
                                csvRow(i) = DBNull.Value
                            Else
                                csvRow(i) = Convert.ToDouble(csvCopy(column))
                            End If
                        Case "DateTime"
                            If String.IsNullOrEmpty(csvCopy(column)) Then
                                csvRow(i) = Nothing
                            Else
                                csvRow(i) = Convert.ToDateTime(csvCopy(column))
                            End If
                        Case "Boolean"
                            If String.IsNullOrEmpty(csvCopy(column)) Then
                                csvRow(i) = DBNull.Value
                            Else
                                csvRow(i) = Convert.ToBoolean(csvCopy(column))
                            End If
                    End Select
                    i += 1
                Next
                datatable.Rows.Add(csvRow)
            End While
        Else
            For Each column As Integer In column2Import
                datatable.Columns.Add(headers(column))
            Next
            While csvCopy.ReadNextRecord()
                Dim csvRow As DataRow = datatable.NewRow
                Dim i As Integer = 0
                For Each column As Integer In column2Import
                    csvRow(i) = csvCopy(column)
                    i += 1
                Next
                datatable.Rows.Add(csvRow)
            End While
        End If
    Else
        If tableAlreadyExist Then
            While csvCopy.ReadNextRecord()
                Dim csvRow As DataRow = datatable.NewRow
                For i = 0 To csvCopy.FieldCount - 1
                    Select Case datatable.Columns(i).DataType.Name
                        Case "String"
                            If String.IsNullOrEmpty(csvCopy(i)) Then
                                csvRow(i) = ""
                            Else
                                csvRow(i) = Convert.ToString(csvCopy(i))
                            End If
                        Case "Int32"
                            If String.IsNullOrEmpty(csvCopy(i)) Then
                                csvRow(i) = DBNull.Value
                            Else
                                csvRow(i) = Convert.ToInt32(csvCopy(i))
                            End If
                        Case "Double"
                            If String.IsNullOrEmpty(csvCopy(i)) Then
                                csvRow(i) = DBNull.Value
                            Else
                                csvRow(i) = Convert.ToDouble(csvCopy(i))
                            End If
                        Case "DateTime"
                            If String.IsNullOrEmpty(csvCopy(i)) Then
                                csvRow(i) = Nothing
                            Else
                                csvRow(i) = Convert.ToDateTime(csvCopy(i))
                            End If
                        Case "Boolean"
                            If String.IsNullOrEmpty(csvCopy(i)) Then
                                csvRow(i) = DBNull.Value
                            Else
                                csvRow(i) = Convert.ToBoolean(csvCopy(i))
                            End If
                    End Select
                Next
                datatable.Rows.Add(csvRow)
            End While
        Else
            For Each header As String In headers
                datatable.Columns.Add(header)
            Next
            While csvCopy.ReadNextRecord()
                Dim csvRow As DataRow = datatable.NewRow
                For i = 0 To csvCopy.FieldCount - 1
                    csvRow(i) = csvCopy(i)
                Next
                datatable.Rows.Add(csvRow)
            End While
        End If
    End If
End Sub

我错过了什么？

Answer 1

以下是解决我的问题的代码：

    'Create a DataTable with the same schema of your DataBase
    Dim ccDataTable As CCListDataTable = New CCListDataTable

    'Import here your csvFile into your new DataTable
    Call ImportCSV2Data(dialog2openFile.FileName, ccDataTable, {0, 2}, True)

    'Merge it with the correct DataTable from your Database (False to recognize the changes)
    Me.HQSdbDataSet.CCList.Merge(ccDataTable, False)

    'Then update your DataBase
    Me.CCListBindingSource.EndEdit()
    Me.CCListTableAdapter.Update(Me.HQSdbDataSet.CCList)

如果在调试模式下关闭应用程序时松动了更改，这是正常的，因为您有两个数据库，一个是应用程序，另一个是调试文件夹，另一个是擦除另一个，当您进入调试模式但是当你启动你的应用程序whitout调试模式就可以了。 其他解决方案：在您的数据库中选择“永不复制”

使用重复键更新tableadapter

1 个答案: