Question

我有一个名为 TimeQuery 的查询。我希望MsgBox会显示所有 [start_hour] 值，其中 [id] = 1然后2等... 我有个问题。当我将使用：

a = DLookup("Hour([start_hour])", "TimeQuery", "[id]=1")

效果很好，但是当使用 [id] =计数器时，它不显示它。在For循环之后我有一个MsgBox，当 [id] =计数器时，它也没有显示MsgBox。怎么了？

For counter = 1 To 3
Dim a As Variant
a = DLookup("Hour([start_hour])", "TimeQuery", "[id]=counter")
MsgBox (counter)
Next
Debug.Print ("")

Answer 1

如果要使用此变量，则需要将变量连接到字符串，如下所示：

For counter = 1 To 3
    Dim a As Variant

    a = DLookup("Hour([start_hour])", "TimeQuery", "[id]=" & counter)
    MsgBox (counter)

Next

Debug.Print ("")

但是，如果要正确执行此操作，请使用记录集

Dim rs As DAO.Recordset
Set rs = CurrentDb.OpenRecordset ("SELECT Hour([start_hour]) As hr FROM TimeQuery WHERE [id] <=3 ORDER BY ID ASC")
Do While Not rs.EOF
   MsgBox rs!hr
   rs.MoveNext
Loop

（VBA）for循环和DLookup（MS ACCESS）

1 个答案: