Datasets and updates

[venerable bede]

If 2 users each have a disconnected dataset which lets say contains a set of customers which they add/amend and delete from then how is the update carried out on the server ?

I can't get my head around this problem with concurrent users and update anomolies.

TIA

[Wokawidget]

I think the last person who updates the last will have their changes saved. Others will be overwritten.

Woka

[venerable bede]

Do the users get any warning woka ?

woof woof

[Wokawidget]

WOOF WOOF!

Errr...no.
It doesn't work like ado in VB6 and an open editable recordset.

Wokkkkkkk

[cfisher]

This maybe a little late in replying, but what I do is date/time stamp when the last record was saved/updated. When the data is viewed to the screen, each row has a date/time stamp of when it was last updated. When they go to perform the update, I check to see if the date/time stamp still matches what's on the screen. If it does, then the record has not been updated since the user viewed that records and it's safe to update now (also update the date/time stamp). If the date/time stamp does not match, then I don't allow the update. It's not 100 % fool proof, but it's pretty close (it eliminated allot of problems here). I can provide more detail if needed.

Chris

[Wokawidget]

I add an UpdateUserID field to the table.
When a user edits a record I set this field to their ID.
This way, you know if it's being editted, and can stop someone editting the same record.

Woka

[nswan]

This maybe a little late in replying, but what I do is date/time stamp when the last record was saved/updated. When the data is viewed to the screen, each row has a date/time stamp of when it was last updated. When they go to perform the update, I check to see if the date/time stamp still matches what's on the screen. If it does, then the record has not been updated since the user viewed that records and it's safe to update now (also update the date/time stamp). If the date/time stamp does not match, then I don't allow the update. It's not 100 % fool proof, but it's pretty close (it eliminated allot of problems here). I can provide more detail if needed.

Chris

This is the way I have always done it in the past as well. Having a business layer helps with this as you can put all the code to deal with the checking of dates and times in there.