Question

我有以下代码从CSV文件导入数据。但是，日期列中的某些值为空，vb.net会出错。我该如何防止这种情况？

    Dim datatabel As New DataTable()
    datatabel.Columns.Add(New DataColumn("PLAASNO", GetType(String)))
    datatabel.Columns.Add(New DataColumn("PLAASNAAM", GetType(String)))
    datatabel.Columns.Add(New DataColumn("BLOKNO", GetType(String)))
    datatabel.Columns.Add(New DataColumn("AREA", GetType(String)))
    datatabel.Columns.Add(New DataColumn("DATUM", GetType(String)))
    datatabel.Columns.Add(New DataColumn("NAME3", GetType(String)))
    datatabel.Columns.Add(New DataColumn("KULTIVAR", GetType(String)))
    datatabel.Columns.Add(New DataColumn("WINGKLAS", GetType(String)))
    datatabel.Columns.Add(New DataColumn("ANALISEDATUM", GetType(Date)))
    datatabel.Columns.Add(New DataColumn("SUIKER", GetType(Decimal)))
    datatabel.Columns.Add(New DataColumn("pH", GetType(Decimal)))
    datatabel.Columns.Add(New DataColumn("SUUR", GetType(Decimal)))


    Dim parser As New FileIO.TextFieldParser("C:\Users\Administrator\Desktop\SKEDULERING\Data\LABANAL2.csv")
    parser.Delimiters = New String() {","}
    parser.HasFieldsEnclosedInQuotes = True

    parser.TrimWhiteSpace = True

    parser.ReadLine()

       Do Until parser.EndOfData = True
           Dim data As String() = parser.ReadFields()
          For i As Integer = 0 To data.Length - 1

             If (String.IsNullOrEmpty(data(i))) Then
    data(i) = DBNull.Value.ToString
               End If
          Next
           datatabel.Rows.Add(data)

        Loop

我怀疑我的问题在于：

             If (String.IsNullOrEmpty(data(i))) Then
                data(i) = DBNull.Value.ToString
             End If

错误是：字符串未被识别为有效的DateTime.Couldn存储在ANALISEDATUM列中。预期类型是DateTime

谢谢。

Answer 1

试试这个。 OLEDB连接将获取excel文件并将其放入数据表中。

                  Public  Shared Function GetCSV as Datatable
                    Dim dt As New DataTable

                                Dim ConStr As String = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" & "YourFile" & ";Extended Properties=""Text;HDR=Yes;FMT=Delimited\"""
                                Dim conn As New OleDb.OleDbConnection(ConStr)
                                Dim da As New OleDb.OleDbDataAdapter("Select * from " & "YOURFILENAME", conn)
                                da.Fill(dt)


                            Return dt

                    End Function

VB.net将空日期导入datatable

1 个答案: