modify records in a DataView with index no. instead of unique ID?

[dwfresh]

HI, I have a question.
I have an XML file with calendar events. When a user clicks on a particular day in my Calendar, the events for that day are shown (using a DataView).

My XML file has this structure:
<Calendar>
<Event>
<ShortDesc>first event</ShortDesc>
<DetailDesc>description</DetailDesc>
<EventDate>12/25/2002</EventDate>
<StartTime>8:00AM</StartTime>
<EndTime>11:30AM</EndTime>
</Event>
<Event>
<ShortDesc>second event</ShortDesc>
<DetailDesc>description</DetailDesc>
<EventDate>12/25/2002</EventDate>
<StartTime>6:00PM</StartTime>
<EndTime>7:30PM</EndTime>
</Event>
..........
</Calendar>

very simple.
I then put the data into a DataView and bind to a DataGrid.

The problem I am having is deleting/updating events in the DataView, which will actually link to the correct underlying Datatable Row.
Is it imperative that I have some sort of 'unique' ID/element/attribute in this XML file, or can I just link the selected index number of the DataView to the correct DataRow in the DataTable ?
What's the best way to accomplish this ?

I'm pretty new to .NET and programming so any help will be greatly appreciated !
thanks!!

 

[link9]

The safest way to do this is to have an eventID. Yes, you could work off of an index#, but if your events somehow got sorted between postbacks, or any other wierdness occured, then you'd update the wrong one.

Heuristic:
ALWAYS ALWAYS ALWAYS have a uniqueID for anything and everything you deal with. Period.

You will save yourself alot of headaches if you always follow that rule.


paul

 

[dwfresh]

Thanks Paul !
I understand... so I have one more silly question.
SO let's say I create another element <EventID> in my XML file.
how would I go about generating a unique ID# to fill this element each time I add a new event?

I was thinking that I could do something like start with 1 and just count up, 1,2,3,4,5,6,7,8. and do somehting like
'int eventid = dataset.Tables[0].Rows.Count + 1;'

but i know this is silly, cuz events will be deleted and I will have events with the same <EventID> #?

so how would someone program this to make sure that each <EventID> # is unique ?

I know this is a total rookie programming question, but any help would be great!!
thanks!!

 

[link9]

Rather than trying to extrapolate the next id from the list (which you could do using the MAX() aggregate function if you want to look into it), I would suggest persisting the currentID perhaps in another file...

Whenever a new record is added, just go there, grab the number, increment it, and close it. Simple and effective.

-paul

 

[dwfresh]

exactly what i was thinking, thanks for the advice paul!!