Question

如何根据日期和时间将多个文本文件导入数据库表并更新数据库而不重复记录的问题：-

Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click

    Dim con As New System.Data.OleDb.OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=|DataDirectory|Student.mdb;Persist Security Info=True")
    Dim cmd As New System.Data.OleDb.OleDbCommand("INSERT INTO [Class] SELECT * FROM [Text;DATABASE=C:\Users\Documents\Visual Studio 2010\Projects\WebApplication10\WebApplication10\App_Data;].[Class.txt]")

    con.Open()
    With cmd
        .Connection = con
        .CommandType = CommandType.Text
        .ExecuteNonQuery()
        MsgBox("File Imported Successfully")
    End With
    con.Close()
End Sub

结束班级

Answer 1

在Access数据库表Class中，确保包含日期和时间字段的字段是主键。这将防止将重复的条目导入表Class。

Answer 2

您可以轻松地将所有文本文件导入到单独的Access表中，或将所有文本文件导入到一个Access表中（假设您感兴趣的文件夹中的每个文件的架构都相同）。

Option Compare Database
Option Explicit
Private Sub Command0_Click()
    Call DoImport
End Sub

Function DoImport()

 Dim strPathFile As String
 Dim strFile As String
 Dim strPath As String
 Dim strTable As String
 Dim blnHasFieldNames As Boolean

 ' Change this next line to True if the first row in CSV worksheet
 ' has field names
 blnHasFieldNames = True

 ' Replace C:\Documents\ with the real path to the folder that
 ' contains the CSV files
 strPath = "C:\your_path_here\"

 ' Replace tablename with the real name of the table into which
 ' the data are to be imported

 strFile = Dir(strPath & "*.txt")

 Do While Len(strFile) > 0
       strTable = Left(strFile, Len(strFile) - 4)
       strPathFile = strPath & strFile

       'DoCmd.TransferText acImportDelim, , strTable, strPathFile, blnHasFieldNames
       DoCmd.TransferText acLinkDelim, , strTable, strPathFile, blnHasFieldNames

 ' Uncomment out the next code step if you want to delete the
 ' EXCEL file after it's been imported
 '       Kill strPathFile

       strFile = Dir()
 Loop

End Function

Private Sub Command1_Click()

Dim strPathFile As String, strFile As String, strPath As String
        Dim strTable As String, strBrowseMsg As String
        Dim blnHasFieldNames As Boolean

        ' Change this next line to True if the first row in EXCEL worksheet
        ' has field names
        blnHasFieldNames = False

        strBrowseMsg = "Select the folder that contains the CSV files:"

        strPath = "C:\your_path_here\"

        If strPath = "" Then
              MsgBox "No folder was selected.", vbOK, "No Selection"
              Exit Sub
        End If

        ' Replace tablename with the real name of the table into which
        ' the data are to be imported
        strTable = "tablename"

        strFile = Dir(strPath & "\*.txt")
        Do While Len(strFile) > 0
              strPathFile = strPath & "\" & strFile

        DoCmd.TransferText acImportDelim, , strTable, strPathFile, blnHasFieldNames

        ' Uncomment out the next code step if you want to delete the
        ' EXCEL file after it's been imported
        '       Kill strPathFile

              strFile = Dir()
        Loop
End Sub

导入多个文本文件以访问数据库

2 个答案: