Question

任何帮助将不胜感激。我试图让这段代码工作。我需要获取临时表的字段名称，并检查它们是否存在使用另一个永久表。我的问题是，抓住变量，我在哪里实际放入字段名称进行检查。？如果我不打算添加字段名称，那么代码会为我做吗？我如何调用该函数才能执行此操作。函数接受和称为strfield的参数，令我困惑的是get names变量是arrStrings。他们不应该匹配吗？

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

你应该可以这样做：

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

不确定你的最终目标是什么，但这应该会给你一个正确的方向。如果你真的想知道两个表中是否存在每个单独的字段，那么像以前一样的数组是一个好主意。

Answer 2

我倾向于返回字典中其他表中的所有字段，因此当您在第一个记录集上循环时，可以避免重复查询。

未测试：

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

VBA-获取字段名称并检查它们是否存在于临时表中

2 个答案: