asp.net – 使用OLEDB读取CSV文件,即使连接字符串中的HDR =否,也会忽略第一行

我们正在将Classic ASP站点转换为ASP.NET站点.其中一项功能是以CSV格式上传“模板”数据,以便导入数据库.那里有几种不同的记录类型(第一个字段总是标识数据的类型).

任务是将CSV转换为DataTable,以便验证它(新项目是要有更好的验证规则)

代码看起来非常简单 – 淡化(取出评论,Try / Catch等),如下所示：

Dim da As New System.Data.OleDb.OleDbDataAdapter
    Dim cn As New System.Data.OleDb.OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & strDirectory & ";" & "Extended Properties=""Text;HDR=No;FMT=Delimited;""")
    Dim cd As New System.Data.OleDb.OleDbCommand("SELECT * FROM " & strCSVFilename,cn)
    cn.Open()
    da.SelectCommand = cd
    da.Fill(dtData)

填充DataTable(dtData),但仅从CSV文件的第二行开始DESPITE“连接字符串”中存在“HDR = No”的事实.

我在这里想念的是什么？

解决方法

Private Sub Test()
    Dim TempDir = My.Computer.FileSystem.SpecialDirectories.Temp
    Dim TempFile = "Test.csv"

    '//Create our test file with a header row and three data rows
    Using FS As New System.IO.FileStream(System.IO.Path.Combine(TempDir,TempFile),IO.FileMode.Create,IO.FileAccess.Write,IO.FileShare.Read)
        Using SW As New System.IO.StreamWriter(FS,System.Text.Encoding.ASCII)
            SW.WriteLine("Col1,Col2")
            SW.WriteLine("R1","R1")
            SW.WriteLine("R2","R2")
            SW.WriteLine("R3","R3")
        End Using
    End Using

    '//Read the data into a table specifying that the first row should be treated as a header
    Using dtData As New DataTable()
        Using da As New System.Data.OleDb.OleDbDataAdapter
            Using cn As New System.Data.OleDb.OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & TempDir & ";" & "Extended Properties=""Text;HDR=Yes;FMT=Delimited;""")
                Using cd As New System.Data.OleDb.OleDbCommand("SELECT * FROM " & TempFile,cn)
                    cn.Open()
                    da.SelectCommand = cd
                    da.Fill(dtData)
                    Trace.WriteLine("With header,expected 3,found " & dtData.Rows.Count)
                End Using
            End Using
        End Using
    End Using

    '//Read the data into a table again,this time specifying that the there isn't a header row
    Using dtData As New DataTable()
        Using da As New System.Data.OleDb.OleDbDataAdapter
            Using cn As New System.Data.OleDb.OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & TempDir & ";" & "Extended Properties=""Text;HDR=No;FMT=Delimited;""")
                Using cd As New System.Data.OleDb.OleDbCommand("SELECT * FROM " & TempFile,cn)
                    cn.Open()
                    da.SelectCommand = cd
                    da.Fill(dtData)
                    Trace.WriteLine("Without header,expected 4,found " & dtData.Rows.Count)
                End Using
            End Using
        End Using
    End Using

    '//Delete our temporary file
    System.IO.File.Delete(System.IO.Path.Combine(TempDir,TempFile))
End Sub

如果您将初始编码更改为Unicode,您将在结果中获得8行和9行,这可能就是您所看到的.如果结果是编码问题,可以将CharacterSet = Unicode添加到扩展属性中.

（编辑：安卓应用网）

【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容!