Question

我有一个表格和一个文本文件。一旦表中的记录复制到textfile中，记录就会被删除。但该表仍在使用中，并将不时插入新记录（由另一个程序）。我要做什么检查如何确保如果表中没有记录，程序将永远不会复制到文本文件中。

任何解决方案或参考都非常感谢。非常感谢你。我在WSH中测试并使用MSSQL Server 2005。

'call functions
  call CopyFile()
  call tblDelete()

Sub tblDelete()
    Dim sql1
    sql1 = "DELETE from tblOutbox"
    rs = conn.Execute(sql1)
End Sub

Sub CopyFile
   'set the sql command
    cmd.CommandText = "SELECT * FROM tblOutbox"
    cmd.CommandType = 1 ''# adCmdText Command text is a SQL query
    Dim rs : Set rs = cmd.Execute
   'create obj for the FileSystem
    Dim objFSO : Set objFSO = CreateObject("Scripting.FileSystemObject")
    Dim objFile, objFolder

    Dim strDir, strFile
    strDir = "c:\"
    strFile = "\newFile.txt"
   'check that the strDirectory folder is exist
    If objFSO.FolderExists(strDir) Then
       Set objFolder = objFSO.GetFolder(strDir)
    Else
       Set objFolder = objFSO.CreateFolder(strDirectory)
       WScript.Echo "Just created " & strDir
    End If
    If objFSO.FileExists(strDir & strFile) Then
       Set objFolder = objFSO.GetFolder(strDir)
    Else
       Set objFile = objFSO.CreateTextFile(strDir & strFile)
       Wscript.Echo "Just created " & strDir & strFile
    End If 
    Set objFile = Nothing
    Set objFolder = Nothing
   'open files and copy into

    Dim objtextStream : Set objtextStream = objFSO.OpenTextFile(strDir & strFile, 8, True)
    Do Until rs.EOF 
       objtextStream.Write rs("id") & ", "

       objtextStream.Write rs("ip") & ", "
       objtextStream.Write rs("msg") & ", "
       objtextStream.WriteLine rs("date")

       rs.MoveNext
    Loop
        objTextStream.WriteLine
        objTextStream.WriteLine "Report Generate at " & Now
        objTextStream.WriteLine "--------------------------------------------"
    objtextStream.Close 
    rs.Close

End Sub

Answer 1

您是否可以使用以下格式设置代码，在此格式中，您可以延迟打开输出文件，直到您触发查询并检索至少一个响应为止：

Set up SQL statement 
Execute SQL query 
init bFirstRecord as true 
Loop over results   
  if bFirstRecord
   check folder and file existence, create as necessary
   open output file
   bFirstRecord = false   
  end if   
  write record to output 
End Loop
Close up files, etc

Answer 2

你可以把

If rs.RecordCount > 0 Then
   exit sub
End If

前

Dim objFSO : Set objFSO = CreateObject("Scripting.FileSystemObject")
Dim objFile, objFolder

即。如果没有记录，请不要执行任何语句。

检查记录是否存在的VBScript

2 个答案: