mysql - ADODB 连接 : UDF using ADODB works fine when called from VBA code, 的有趣问题，但从 EXCEL 单元格调用时返回错误

Question

我一直在 Excel 中使用 ADODB 连接，以便连接到 MySql 数据库并检索值。

我的代码的本质如下:

Public Function ODPH(B0 As Range, sqlstr As Variant)


Dim oconn As ADODB.Connection
Dim rs As ADODB.Recordset


On Error GoTo error_handler



'Connect to MySql. Assign default values if connection string is missing!

ipDriver = "{MySQL ODBC 5.2 Unicode Driver}"
ipType = "MySql"
If IsEmpty(ipHost) Then ipHost = "HHHH"
If IsEmpty(ipUser) Then ipUser = "UUUU"
If IsEmpty(ipdbName) Then ipdbName = "DDDD"
If IsEmpty(ipPasswd) Then ipPasswd = "PPPP"

strConn = "DRIVER=" & ipDriver & ";" & _
"SERVER=" & ipHost & ";" & _
"DATABASE=" & ipdbName & ";" & _
"USER=" & ipUser & ";" & _
"PASSWORD=" & ipPasswd & ";" & _
"Option=" & ipOption

Set oconn = New ADODB.Connection
oconn.Open strConn

oconn.CursorLocation = adUseClient
'oconn.CursorLocation = adUseServer

Set rs = New ADODB.Recordset
' rs.Open sqlstr, oconn, adLockOptimistic
' rs.Open sqlstr, oconn, adLockReadOnly
rs.Open sqlstr, oconn, adOpenStatic, adLockOptimistic
rs.Open sqlstr, oconn

If rs.EOF Then
'MsgBox "No records returned!"
    ODPH = "#No record at db"
    Exit Function

    Else
    'rs.MoveLast
    rCount = rs.RecordCount
    Select Case rCount
        Case Is > 1
            ODPH = "#many records from db"
            Exit Function

        Case Else

            Select Case rs.Fields.Count
                Case Is > 1
                ODPH = "#many columns from db"
                Exit Function

                Case Else
                Select Case IsNull(rs.Fields(0).Value)

                    Case Is = True
                        ODPH = "#null at db"
                        Exit Function

                    Case Else
                        aux = rs(0).Value
                        Select Case IsNumeric(aux)
                            Case Is = True
                            ODPH = CDbl(aux)
                            Exit Function

                            Case Else
                            ODPH = aux
                            Exit Function
                        End Select

                End Select
        End Select

    End Select

End If

'Error handler
error_handler:
    ODPH = Err.Description
    Exit Function

End Function

我的问题是:

• 此代码在从另一个 VBA 子程序或函数调用时运行良好。
• 但是当从一个 excel 单元格中调用此函数作为 UDF 函数时，它会返回以下错误:

“参数类型错误、超出可接受范围或相互冲突。” (错误编号 3001)

我真的不明白为什么一组代码在被 VBA 编辑器调用时不返回错误，而当它作为用户定义函数从一个 excel 单元格调用时却返回此错误!

感谢任何帮助。

最好的问候，

Answer 1

根据定义，UDF 需要返回一些东西，而您缺少返回类型，例如:

Public Function ODPH(B0 As Range, sqlstr As Variant) As Variant

从另一个宏调用它是可行的，因为 VBA(或几乎所有编程语言)并不关心您是否有函数的接收变量。