如何避免来自 VBA Excel 的空查询的 Power Query 错误？

Question

我想将一个文本文件导入 Excel，通过 VBA 宏过滤我想要的内容。数据量很大，所以我有效地使用了 Power 查询。我有一个列表，其中列出了要以不同方式过滤和处理的几件事，并且此列表可能会更改。因此，对于要过滤的每个“功能”，我都会在新工作表中重新加载查询。 如果过滤器使查询为空，我会从 Power Query 中收到一个我无法跳过的错误：

Application.EnableEvents = False
Application.ScreenUpdating = False
Application.DisplayAlerts = False 

调试我看到在查询创建和粘贴到工作表之间出现错误，见下面代码中的（*）。

有人知道是否有办法将记录数放入查询中，以便能够使用 if 语句并跳过粘贴阶段？

我唯一的另一个想法是为每个特征自动写入一行到 txt 文件中进行过滤，但这不是一个优雅的方法

我不明白的事情是使用函数出现问题，见下文，但不直接使用宏。 当我使用该函数时，显示的错误并不总是出现，但无论如何代码完成了函数但主宏停止了。

test.txt

946737295   9CE78280    FF  1   5   FF  FF  FF  FF  FF
946737295   9CE78280    C0  FF  0   0   0   0   FF  FF
946737295   9CE68082    C0  4   0   FF  FF  FF  FF  FF

宏是：

Function readTxt(input_path As String, Pgn As String, B2 As String, B3 As String) As Boolean

    Dim Wb As Workbook
    Dim Ws As Worksheet
    Dim Conn As WorkbookConnection
    Dim mFormula As String
    Dim query As WorkbookQuery
    
    Set Wb = ActiveWorkbook
    Set Ws = Wb.ActiveSheet
    
    On Error Resume Next
    
    Application.EnableEvents = False
    Application.ScreenUpdating = False
    Application.DisplayAlerts = False
       

    mFormula = "let " & _
        "Source = Csv.Document(File.Contents(""" & input_path & """),[Delimiter=""#(tab)"", Columns=10, Encoding=65001, QuoteStyle=QuoteStyle.Csv])," & _
        "#""Step1"" = Table.SelectRows(Source, each Text.Contains([Column2], """ & Pgn & """) and [Column5] = """ & B3 & """ and [Column4] = """ & B2 & """)," & _
        "#""Step2"" = Table.RemoveColumns(Step1,{""Column2"", ""Column3"", ""Column4"", ""Column5"", ""Column9"", ""Column10""})" & _
        "in #""Step2"""
    
    Set query = Wb.Queries.Add("test_7", mFormula)

    With Ws.ListObjects.Add(SourceType:=0, Source:= _
         "OLEDB;Provider=Microsoft.Mashup.OleDb.1;Data Source=$Workbook$;Location=" & "test_7" & ";Extended Properties=""""", Destination:=Ws.Range("A3"), XlListObjectHasHeaders:=xlYes).QueryTable
         '.ListObject.TotalsRowRange
         .CommandType = xlCmdSql
         .AdjustColumnWidth = False
         .ListObject.Name = "test"
         .CommandText = "SELECT * FROM [" & "test_7" & "]" 
         .Refresh BackgroundQuery:=False
     End With
         
     If Err.Number <> 0 Then
            Err.Clear
     End If
      
      query.Delete
         
    Application.EnableEvents = True
    Application.ScreenUpdating = True
    Application.DisplayAlerts = True
    
    readTxt = True 'output
    
    On Error GoTo 0

End Function

Sub readTxt()
Dim Wb As Workbook
Dim Ws As Worksheet
Dim Conn As WorkbookConnection
Dim mFormula As String
Dim query As WorkbookQuery

Set Wb = ActiveWorkbook

Dim i As Integer
Dim C3 As String

    On Error Resume Next
    
    Application.EnableEvents = False
    Application.ScreenUpdating = False
    Application.DisplayAlerts = False

C3 = "F2"

For i = 1 To 2
       
    If i = 2 Then
        C3 = "FF"
        Sheets.Add After:=ActiveSheet
    End If
    Set Ws = Wb.ActiveSheet

    mFormula = "let " & _
        "Source = Csv.Document(File.Contents(""C:\test.txt""),[Delimiter=""#(tab)"", Encoding=65001, QuoteStyle=QuoteStyle.Csv])," & _
        "#""Step1"" = Table.SelectRows(Source, each Text.Contains([Column2], ""E7"") and [Column3] = """ & C3 & """)" & _
        "in #""Step1"""
        
    Set query = Wb.Queries.Add("Test_text", mFormula)
    
    ' (*) THE ERROR OF POWER QUERY APPEARS HERE
    
    With Ws.ListObjects.Add(SourceType:=0, Source:= _
         "OLEDB;Provider=Microsoft.Mashup.OleDb.1;Data Source=$Workbook$;Location=" & "Test_text" & ";Extended Properties=""""", Destination:=Ws.Range("A3"), XlListObjectHasHeaders:=xlYes).QueryTable
         .CommandType = xlCmdSql
         .AdjustColumnWidth = False
         .ListObject.Name = "test"
         .CommandText = "SELECT * FROM [" & "Test_text" & "]"
         .Refresh BackgroundQuery:=False
     End With
     
     query.Delete
 
Next

    Application.EnableEvents = True
    Application.ScreenUpdating = True
    Application.DisplayAlerts = True
    
    On Error GoTo 0
      
End Sub

谢谢， 鲁杰罗

Answer 1

您可以使用此代码检查步骤（表）是否具有某些特定列：

let Source = Csv.Document(File.Contents("C:\temp\test.txt"),[Delimiter=";", Encoding=65001, QuoteStyle=QuoteStyle.Csv]),
    #"Step1" = Table.SelectRows(Source, each Text.Contains([Column2], "E7") and [Column3] = "F1"),
    result_error = "Some error",
    check_columns = Table.HasColumns(#"Step1", {"Column2", "Column3"}),
    result = if check_columns = true then #"Step1" else result_error
in result

查看 check_columns 步骤和条件结果