没有为一个或多个必需参数指定值（访问）

Question

我有 2 个包含这些字段的数据表

*数据排序器

1. 存档日期/时间（datetimepicker，它已经是数据）

2. 存储短文本（组合框）

3. BulanOrdner ShortText（组合框）

4. TahunOrdner 日期/时间 (datetimepicker)

*datalemari

1. 存档日期/时间（datetimepicker，它已经是数据）

2. 存储短文本（组合框）

3. Lemari 短文本（组合框）

4. BulanOrdner ShortText（组合框）

5. TahunOrdner 日期/时间 (datetimepicker)

现在我很困惑为什么我错了

我尝试过的：

我已经完成了我的代码，但总是出现错误“没有给出更多的价值......”

我在组合框（存储）中使用 if else 调用 2 表

这些是我的代码序列，我认为组合框中的选定项目都是如此

注意：

存储 = 组合框

Private Sub storage_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles storage.SelectedIndexChanged
If storage.SelectedIndex = 1 Then
    groupordner.Visible = True
    grouplemari.Visible = False
Else
    If storage.SelectedIndex = 2 Then
        groupordner.Visible = False
        grouplemari.Visible = True
    End If
End If
End Sub

Private Sub save_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles save.Click
If storage.SelectedItem = "Ordner" Then
    str = "Update dataordner set Storage = " & storage.Text & ", BulanOrdner = " & bulanordner.Text & ", TahunOrdner = '" & tahunordner.Value & "' Where Archive = '" & tanggalarchive.Value & "'"
    proses.ExecuteNonQuery(str)
    MsgBox("Data Has Been Saved", MessageBoxButtons.OK)
    Call bersih()
    Call data_penjualan()
Else
    If storage.SelectedItem = "Lemari" Then
        str = "Update datalemari set Storage = " & storage.Text & ", Lemari = " & lemari.Text & ", BulanLemari = " & bulanlemari.Text & ", TahunLemari = '" & tahunlemari.Value & "' Where Archive = '" & tanggalarchive.Value & "'"
        proses.ExecuteNonQuery(str)
        MsgBox("Data Has Been Saved", MessageBoxButtons.OK)
        Call bersih()
        Call data_penjualan()
    End If
End If
End Sub

Answer 1

可能有一些控件的值是null 或Nothing，您可以使用断点调试来检查空值或者可能存在未初始化的对象。

你也可以试试下面的代码：

注意：我会建议你改用参数化查询

  Private Sub save_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles save.Click
        If storage.SelectedItem Is Nothing Then
            MsgBox("Plese Select the item first", MsgBoxStyle.Exclamation)
        Else

            If conn.State <> ConnectionState.Open Then
                conn.Open() '' Assuming conn is your OleDbConnection
            End If
            Dim cmd As OleDbCommand = conn.CreateCommand
            Try
                If storage.SelectedItem = "Ordner" Then
                     Str = "Update dataordner set Storage = " & storage.Text & ", BulanOrdner = " & bulanordner.Text & ", TahunOrdner = '" & tahunordner.Value & "' Where Archive = '" & tanggalarchive.Value & "'"
                    cmd.CommandText = Str
                    cmd.ExecuteNonQuery()
                    MsgBox("Data Has Been Saved", MessageBoxButtons.OK)
                    Call bersih()
                    Call data_penjualan()
                Else
                    If storage.SelectedItem = "Lemari" Then
                        Str = "Update datalemari set Storage = " & storage.Text & ", Lemari = " & lemari.Text & ", BulanLemari = " & bulanlemari.Text & ", TahunLemari = '" & tahunlemari.Value & "' Where Archive = '" & tanggalarchive.Value & "'"
                        cmd.CommandText = Str
                        cmd.ExecuteNonQuery()
                        MsgBox("Data Has Been Saved", MessageBoxButtons.OK)
                        Call bersih()
                        Call data_penjualan()
                    End If
                End If
            Catch ex As Exception
                MsgBox(ex.Message, MsgBoxStyle.Exclamation)
            Finally
                conn.Close()
            End Try

        End If
 End Sub