将数据导出到 csv 文件

Question

我想将数据从数据表导出到 csv 文件。

当您STU_NAMES学生姓名分组时，CSV 文件中显示的列数将从 0 到最后一个值的数字形式出现。 当分组STU_TEST时，每一行都在 csv 文件中 标注 数据根据列中的值和数字水平显示每个学生的数据

结果

我用于导出文本文件数据的方法。 数据是原样的，而不是垂直的。

Blockquote

Public Sub csvexportd(ByVal dT As DataTable, ByVal filpath As String)
Dim thecsvfile As String = String.Empty
     Dim nameHeader0 = dT.Columns(1).ColumnName.ToString   
    Dim nameHeader1 = dT.Columns(2).ColumnName.ToString   
    Dim nameHeader2 = dT.Columns(3).ColumnName.ToString   
    

    thecsvfile &= String.Join(",", {nameHeader0, nameHeader1, nameHeader2}) & vbNewLine  



    Dim I As Single = 0  
    For I = 0 To dT.Rows.Count - 1  
        If dT Is Nothing Then  
            Exit For : Exit Sub  

        End If  

        '//  
        Dim nameValue0 = ""  
        Dim nameValue1 = ""  
        Dim nameValue2 = ""  
        
        
        '//  

         
            nameValue0 = dT.Rows(I).Item(0).ToString()  
            nameValue1 = dT.Rows(I).Item(1).ToString()  
            nameValue2 = dT.Rows(I).Item(2).ToString()  
           

            'thecsvfile &= String.Join(",", {nameValue0, nameValue1, nameValue2}) & vbNewLine  

        End If  

    Next  
    thecsvfile = thecsvfile.Trim  

    My.Computer.FileSystem.WriteAllText(Application.StartupPath & "\Excel\" & filpath & now & ".csv", thecsvfile, False)  
     
End Sub  

Note：此问题总结整理于: Export data to csv file

Answer 1

您可以参考以下方法生成表格：

    Public Function GenerateTable(ByVal sourceTable As DataTable) As DataTable  
        Dim newTable As DataTable = New DataTable()  
        newTable.Columns.Add("STU_TEST")  
        Dim TArr As List(Of String) = New List(Of String)()  
  
        For Each row As DataRow In sourceTable.Rows  
            Dim columnName As String = row.ItemArray(0).ToString()  
            Dim rowName As String = row.ItemArray(2).ToString()  
  
            If Not newTable.Columns.Contains(columnName) Then  
                newTable.Columns.Add(columnName)  
            End If  
            If Not TArr.Contains(rowName) Then  
                TArr.Add(rowName)  
            End If  
        Next  
        For Each TValue As String In TArr  
            Dim row As DataRow = newTable.NewRow()  
            row(0) = TValue  
  
            For i As Integer = 1 To newTable.Columns.Count - 1  
                row(i) = sourceTable.AsEnumerable().Where(Function(x) (x.Field(Of String)("STU_NAME") = newTable.Columns(i).ColumnName) AndAlso (x.Field(Of String)("STU_TEST") = TValue)).Select(Function(x) x.Field(Of String)("STU_RATE")).FirstOrDefault()  
            Next  
            newTable.Rows.Add(row)  
        Next  
        Return newTable  
    End Function  

我的测试中的代码：

        Dim dt As DataTable = New DataTable()  
        dt.Columns.Add("STU_NAME")  
        dt.Columns.Add("STU_RATE")  
        dt.Columns.Add("STU_TEST")  
        dt.Rows.Add("ALIE", "0", "T1")  
        dt.Rows.Add("SAIED", "", "T1")  
        dt.Rows.Add("EBRAHIM", "#", "T1")  
        dt.Rows.Add("ALIE", "0", "T2")  
        dt.Rows.Add("SAIED", "NOT", "T2")  
        dt.Rows.Add("EBRAHIM", "1", "T2")  
        dt.Rows.Add("SALIM", "NOT", "T2")  
        dt.Rows.Add("MAHER", "2", "T2")  
        Dim newTable As DataTable = GenerateTable(dt)  

Result:

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