Sql 在vb.net中显示等于0的行时出错
我目前正在为一家酒店开发预订系统。我想显示房间是否可用时出错。当某个日期没有预订房间时,数据将显示,以便他们可以预订房间。但是当房间不可用时,我想要一条消息说房间不可用,但它不断出现错误,停止程序 我尝试过一个if语句,但它没有起作用,尽管我可能做得不对,因为我是一个初学者 下面是调用select语句以显示可用房间的代码Sql 在vb.net中显示等于0的行时出错,sql,vb.net,Sql,Vb.net,我目前正在为一家酒店开发预订系统。我想显示房间是否可用时出错。当某个日期没有预订房间时,数据将显示,以便他们可以预订房间。但是当房间不可用时,我想要一条消息说房间不可用,但它不断出现错误,停止程序 我尝试过一个if语句,但它没有起作用,尽管我可能做得不对,因为我是一个初学者 下面是调用select语句以显示可用房间的代码 Protected Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.C
Protected Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim SearchDB As New HotelTableAdapters.Room_TypeTableAdapter
Dim GetAvailaibility As Hotel.Room_TypeDataTable = SearchDB.GetDataByRoomAvailability(DDRoomType.Text, Calendar1.SelectedDate.ToShortDateString())
Dim RoomDescription As String = GetAvailaibility(0)("Description")
Dim Price As Integer = GetAvailaibility(0)("Room_TariffID")
Dim Roomtypeid As Integer = GetAvailaibility(0)("Room_TypeID")
Dim DateCheckin As Date = Calendar1.SelectedDate.ToShortDateString
IDlabel.Text = Roomtypeid
roomlabel.Text = RoomDescription
pricelabel.Text = Price
Session("Room_TypeID") = Roomtypeid
Session("Description") = RoomDescription
Session("Check_in_date") = DateCheckin
Session("Room_TarriffID") = Price
尝试了这个if语句,但仍然没有成功
If GetAvailability.Rows.Count > 0 Then Label1.text = ("Room unavailable")
更新:
如果这句话现在行得通,我就把它放在正确的地方了
If GetAvailability.Rows.Count > 0 then
Dim RoomDescription As String = GetAvailaibility(0)("Description")
Dim Price As Integer = GetAvailaibility(0)("Room_TariffID")
Dim Roomtypeid As Integer = GetAvailaibility(0)("Room_TypeID")
Dim DateCheckin As Date = Calendar1.SelectedDate.ToShortDateString
IDlabel.Text = Roomtypeid
roomlabel.Text = RoomDescription
pricelabel.Text = Price
Session("Room_TypeID") = Roomtypeid
Session("Description") = RoomDescription
Session("Check_in_date") = DateCheckin
Session("Room_TarriffID") = Price
Else Label1.text = ("Room Unavailable")
如果没有任何行,则无法访问
(0)
索引,因为它不存在<代码>如果GetAvailability.Rows.Count>0,则感谢您的回复!我确实试过了,但没有成功!你必须用你所尝试的更新你的帖子。你必须把整个代码块放在If-Then
块中。请记住,如果没有任何行,就不能使用GetAvailability(0)
。除了GetAvailability(0)之外,还有什么我可以使用的吗?