VBA-獲取字段名稱並檢查它們是否存在臨時表中

Question

任何幫助將不勝感激。我試圖讓這個代碼工作。我需要獲取臨時表的字段名稱，並檢查它們是否存在使用另一個永久表。我的問題是，逮捕變量，我在哪裏實際放在字段名稱來檢查。 ？如果我不打算添加字段名稱，代碼會爲我執行嗎？我該如何調用函數才能做到這一點。該函數接受和參數稱爲strfield和什麼令我困惑的是get名稱變量是arrStrings。他們不應該匹配嗎？

Sub Example() 
Dim objRecordset As ADODB.Recordset 
Dim arrStrings(1 To 100) As String 
Dim intIndex As Integer 
Dim i As Integer 

Set objRecordset = New ADODB.Recordset 
objRecordset.ActiveConnection = CurrentProject.Connection 
objRecordset.Open ("MyTable1") 
intIndex = 1 
'loop through table fields 
For i = 0 To objRecordset.Fields.Count - 1 
arrStrings(intIndex) = objRecordset.Fields.Item(i).Name 
  
intIndex = intIndex + 1 
  
Next i 
End Sub 


' this is the function that checks the exists 

Function CheckExists(ByVal strField As String) As Boolean 
Dim objRecordset As ADODB.Recordset 
Dim i As Integer 

Set objRecordset = New ADODB.Recordset 
objRecordset.ActiveConnection = CurrentProject.Connection 
objRecordset.Open ("MyTable2") 
'loop through table fields 
For i = 0 To objRecordset.Fields.Count - 1 
'check for a match 
  
If strField = objRecordset.Fields.Item(i).Name Then 
  
'exit function and return true 
  
CheckExists = True 
  
Exit Function 
  
End If 
  
Next i 
'return false 
CheckExists = False 
End Function 

Answer 1

你應該能夠做這樣的事情：

Option Explicit 


Sub Example() 
    Dim objRecordset As ADODB.Recordset 
    Dim intNumExist As Integer 
    Dim i As Integer 

    Set objRecordset = New ADODB.Recordset 
    objRecordset.ActiveConnection = CurrentProject.Connection 
    objRecordset.Open ("MyTempTable") 

    'loop through table fields, see if they exist in other table 
    For i = 0 To objRecordset.Fields.Count - 1 
     intNumExist = intNumExist + CheckExists(objRecordset.Fields.Item(i).Name) 
    Next i 

    Debug.Print intNumExist & "fields exist in both tables" 

End Sub 

Function CheckExists(ByVal strField As String) As Integer 
    Dim objRecordset As ADODB.Recordset 
    Dim i As Integer 

    Set objRecordset = New ADODB.Recordset 
    objRecordset.ActiveConnection = CurrentProject.Connection 
    objRecordset.Open ("MyPermTable") 
    'loop through table fields 
    For i = 0 To objRecordset.Fields.Count - 1 
     'check for a match ? 
     If strField = objRecordset.Fields.Item(i).Name Then 
      'exit function and return true (1) 
      CheckExists = True 
      Exit Function 
     End If 
    Next i 
    'return false 
    CheckExists = False 

    CheckExists = Abs(CheckExists) 
End Function 

不知道你的最終目標是什麼，但是這應該給你一個正確的方向點。如果你真的想看看每個單獨的字段是否存在於兩個表中，那麼像你之前的數組是一個好主意。

Answer 2

我傾向於返回字典中其他表中的所有字段，因此避免了在循環第一個記錄集時重複查詢。

未經測試：

Sub Example() 

    Dim objRecordset As ADODB.Recordset 
    Dim arrStrings(1 To 100) As String 
    Dim intIndex As Integer 
    Dim f As Field, dict As Scripting.Dictionary 

    Set objRecordset = New ADODB.Recordset 
    objRecordset.ActiveConnection = CurrentProject.Connection 
    objRecordset.Open "MyTable1" 

    'get the list of fields for the other table 
    Set dict = GetTableFields("MyOtherTable") 

    For Each f In objRecordset.Fields 
     If dict.Exists(f.Name) Then 
      'have matching field in MyOtherTable 
     Else 
      'no matching field in MyOtherTable 
     End If 
    Next f 

End Sub 

'return all the field names for the provided table name 
Function GetTableFields(ByVal sTable As String) As Scripting.Dictionary 
    Dim objRecordset As ADODB.Recordset 
    'add reference to "Microsoft Scripting Runtime" 
    Dim dict As New Scripting.Dictionary 
    Dim f As Field 

    Set objRecordset = New ADODB.Recordset 
    objRecordset.ActiveConnection = CurrentProject.Connection 
    'you don't need any records: just the fields 
    objRecordset.Open "select * from " & sTable & " where false" 
    'collect all the field names... 
    For Each f In objRecordset.Fields 
     dict.Add f.Name 
    Next f 
    Set GetTableFields = dict 'return the dictionary (note "Set"...) 
End Function