Question

我的代码仅适用于第一个项目，但不适用于多个项目。我如何得到最好的帮助

Public Sub saveItemListview(lstview As ListView)
    Try
        con = New SqlConnection(My.Settings.StockConnectionString)
        If con.State = ConnectionState.Closed Then
            con.Open()
        End If

        sql = "insert into salestb values(@items,@quantity,@price)"

        Dim cmd As SqlCommand = New SqlCommand(sql, con)

        For Each item As ListViewItem In lstview.Items
            cmd.Parameters.AddWithValue("@Items", item.Text.ToString.Trim)
            cmd.Parameters.AddWithValue("@quantity", item.SubItems(1).Text.ToString.Trim)
            cmd.Parameters.AddWithValue("@Price", item.SubItems(2).Text.ToString.Trim)
            cmd.ExecuteNonQuery()
            cmd.Dispose()
        Next

        MsgBox("Save Successsfully")
        con.Close()
    Catch ex As Exception
        MsgBox(ex.Message)
    End Try
End Sub

Public Sub saveItemListview(lstview As ListView)
    Try
        con = New SqlConnection(My.Settings.StockConnectionString)
        If con.State = ConnectionState.Closed Then
            con.Open()
        End If

        sql = "insert into salestb values(@items,@quantity,@price)"

        Dim cmd As SqlCommand = New SqlCommand(sql, con)

        For Each item As ListViewItem In lstview.Items
            cmd.Parameters.AddWithValue("@Items", item.Text.ToString.Trim)
            cmd.Parameters.AddWithValue("@quantity", item.SubItems(1).Text.ToString.Trim)
            cmd.Parameters.AddWithValue("@Price", item.SubItems(2).Text.ToString.Trim)
            cmd.ExecuteNonQuery()
            cmd.Dispose()
        Next

        MsgBox("Save Successsfully")
        con.Close()
    Catch ex As Exception
        MsgBox(ex.Message)
    End Try
End Sub

如果我尝试了多个项目，则会显示错误消息：

变量名“ @items”已声明。变量名必须在查询批处理或存储过程中始终是唯一的。

Answer 1

Public Sub saveItemListview(lstview As ListView)
    Try
        con = New SqlConnection(My.Settings.StockConnectionString)
        If con.State = ConnectionState.Closed Then
            con.Open()
        End If

        sql = "insert into salestb values(@items,@quantity,@price)"

        Dim cmd As SqlCommand = New SqlCommand(sql, con)

        For Each item As ListViewItem In lstview.Items
            cmd.Parameters.AddWithValue("@Items", item.Text.ToString.Trim)
            cmd.Parameters.AddWithValue("@quantity", item.SubItems(1).Text.ToString.Trim)
            cmd.Parameters.AddWithValue("@Price", item.SubItems(2).Text.ToString.Trim)
            cmd.ExecuteNonQuery()
            cmd.Dispose()
            cmd.Parameter.clear()
        Next

        MsgBox("Save Successsfully")
        con.Close()
    Catch ex As Exception
        MsgBox(ex.Message)
    End Try
End Sub

如何将ListView中的多个项目保存到SQL数据库中？

1 个答案: