在 VBA 的查询中使用声明字符串的更简单方法

Question

我正在编写一个宏，它应该运行查询以将数据从 excel 传输到 Access 数据库，并且一切正常，但是，如果我想在其中一个查询中使用字符串，我必须键入它们像这样：

'" & Lijn & "'

我知道以下代码（用 VBA 编写）通过使用问号和 setString 更容易用 Javascript 编写：

VBA：

Dim ShiftsQ As String
ShiftsQ = "INSERT INTO Shifts(Lijn, Operator, Ploeg, Teamleider) VALUES ('" & Lijn & "', '" & Operator & "', '" & Ploeg & "', '" & Teamleider & "');"

Javascript：

var ShiftsQ = SQL.prepareStatement(INSERT INTO Shifts(Lijn, Operator, Ploeg, Teamleider) VALUES (?, ?, ?, ?);
ShiftsQ.setString(1, Lijn);
ShiftsQ.setString(2, Operator);
ShiftsQ.setString(3, Ploeg);
ShiftsQ.setString(4, Teamleider);

有没有像 Javascript 那样编写 VBA 代码？

Answer 1

据我所知，没有什么比 .NET string.Format() 方法 VBA 更好的了。但是您可以编写自己的此类函数版本，该函数使用代理并返回格式化的字符串。

Private Sub Main()
    '   Your actual query
    '   The deputys are indexed in curley brackets (inspired from the .NET syntax of the equivalent function, making your code easy to read for .NET programmers)
    Dim qry As String
    qry = "SELECT {0}, {1} FROM {2} WHERE {3}"

    '   The values to set for the deputys in your query
    Dim parameters(3) As String
    parameters(0) = "firstname"
    parameters(1) = "lastname"
    parameters(2) = "users"
    parameters(3) = "userID = 'M463'"

    '   For demo purposes, this will display the query in a message box
    '   Instead of the MsgBox, you would use the formatted query to execute against the database
    MsgBox FormatString(qry, parameters)
End Sub

'   This is where the magic happens, the deputys in the given string will be replaced with the actual values from the provided array
Private Function FormatString(strInput As String, paramValues() As String)
    '   This will be our return value
    Dim strOutput As String
    strOutput = strInput

    '   Verify that the given count of parameters matches the given count of deputys in the input string
    Dim maxParamIndex As Integer
    maxParamIndex = UBound(paramValues)

    Dim deputyCount As Integer

    For i = 1 To Len(strOutput) + 1 Step 1
        If Mid(strOutput, i, 3) = "{" & deputyCount & "}" Then
            deputyCount = deputyCount + 1
        End If
    Next

    '   If there is a mismatch between the count of parameters and the count of deputys, display exception message and exit the function
    '   Adding +1 to maxParamIndex is neccessary, as maxParamIndex refers to the maximum index (starting at 0, not 1) of the given array and deputyCount refers to the actual count of deputys (starting at 1)
    If maxParamIndex + 1 <> deputyCount Then
        MsgBox "Number of deputys has to match number of parameters for the given string:" & vbCrLf & strInput, vbCritical, "Exception in Function FormatString"
        FormatString = ""
    End If

    '   Iterate through the array and replace the deputys with the given values
    For i = 0 To maxParamIndex Step 1
        strOutput = Replace(strOutput, "{" & i & "}", paramValues(i))
    Next

    '   return the formatted string
    FormatString = strOutput
End Function

示例结果：

Answer 2

如果我遇到这个问题，我会简单地自己解决它（尽管可能有其他“标准”解决方案），方法是定义我自己的简单全局函数（放入任何标准代码模块中）

Public Function S_(str as String) as String
    S_ = chr(39) & str & chr(39)
End Function

ShiftsQ = "INSERT INTO Shifts(Lijn, Operator, Ploeg, Teamleider) VALUES (" & S_(Lijn) & ", " & S_(Operator) & ", " & S_(Ploeg) & ", " & S_(Teamleider) & ");"

这样，我将在我的所有项目中遵循一个简单而系统的规则，即在我的查询中对任何文本类型的参数调用S_(param)...