Question

我有一个文本框，用户输入要更新/编辑的行的ID。当他们输入存在的ID时，我让它正常工作，但是当他们输入不存在的ID或者将它留空时我收到错误。

目标：

允许空白 - 如果用户将该字段留空，则需要擦除表单并让用户继续（不需要消息框）。
当ID无效时，通过消息框警告用户。

当前代码

Private Sub Text135_LostFocus()

    If Me.Text135 = Nothing Then

    MsgBox "Nothing entered into the ID field. Query will not run"

    GoTo Last_Line:

    Else

    sql = "SELECT * FROM tbl_Downtime WHERE ID = " & Forms![DTForm]![Text135] & ";"
    Set db = CurrentDb
    Set rs = db.OpenRecordset(sql)

    Me.Text126.Value = rs!production_date
    Me.Text144.Value = rs!shift
    Me.Text116.Value = rs!job
    Me.Text118.Value = rs!suffix
    Me.Text121.Value = rs!reason
    Me.Text123.Value = rs!downtime_minutes
    Me.Text4.Value = rs!people_missing
    Me.Text128.Value = rs!comment
    Set db = Nothing
    Set rs = Nothing

    Last_Line:

    End If

End Sub

Answer 1

当字段为空时，完全停止执行sub：
```
If Nz(Me.Text135) = "" Then 'Text135 is null or empty

    Exit Sub

End If
```
但如果您问题中的代码是您的实际代码（而不仅仅是缩短的示例），那么您既不需要Exit Sub也不需要GoTo Last_Line:部分，因为之后在消息框中，代码执行将跳转到End If。

检查Recordset是否包含任何行：

Set db = CurrentDb
Set rs = db.OpenRecordset(sql)

If rs.EOF Then

    'rs.EOF is True when there are no rows
    MsgBox "ID is not valid"

Else

    'do stuff

End If

Set db = Nothing
Set rs = Nothing

Access VB：验证文本框中的空白值和不正确的值

1 个答案: