Grid Component(How to Store Previous Value)

[JetLi]

How do I store the previous value of a field if it is changed from its original value to a new field upon saving or updating the record?
e.g. I have a products table field the following fields, ProductID, ItemDescription,Price,LastPrice.
When I change the value of the price field then it will update the value on the LastPrice field.

e.g
Product ID ITem Price LastPrice
1 Sample Item 10 9

If I now change the Price to 15 then the lastPrice would now be 10.

Thanks!

[RichCPT]

Re: Grid Component(How to Store Previous Value)

Look in the grid builder for the "CanUpdateRecord" event under "code / Servier-side Events.

Put a debug(1) statement in that event and run under Working Preview. If you examine the "DataSubmitted" argument you will find a "DataSubmitted.oldValues" pointer variable to all the original values. You'd want to include the "lastPrice" field in the grid or detailView view, so you can just set a new value for it in the "CanUpdateRecord" event. I update my "last user change date" and "last user change id" fields in this event. On my form I put these fields within a Frame within a Container that is normally Hidden via a session variable setting. The normal user does not see these fields, but a system administrator can turn these fields on for display. If the field being updated like this is a really important field then I prefer using a database trigger.

[GGandhi]

Re: Grid Component(How to Store Previous Value)

hello

is this an updatable grid?
or
is this on a detail view of a read only with an updatable detail view.
either way
call a xbasic function that fires when the data on the price changes and the xbasic function sets the value of the last price equal to the price.

[JetLi]

Re: Grid Component(How to Store Previous Value)

Thanks Govindan and Rich for trying to help. I managed to try using Triggers like what Rich did/suggested. Hope Gandhi will post the Alpha Code here While I post the Sql Server Trigger Code.

CREATE TRIGGER tr_u_stocks_ForUpdate
on stocks
FOR UPDATE
AS
BEGIN
Declare @stckid int
Declare @OldPrice money, @NewPrice money

Select * into #TempTable
from inserted

While(Exists(Select stckid from #TempTable))
Begin
Select TOP 1 @stckid = stckid, @NewPrice = retail
FROM #TempTable

Select @OldPrice = retail from deleted
WHERE stckid= @stckid

Update R set R.LastPrice=@OldPRice FROM stocks AS R WHERE stckid=@stckid

End
END

[GGandhi]

Re: Grid Component(How to Store Previous Value)

okay here is the code

dim lastPrice as n
dim newPrice as n
lastPrice = e._currentRowDataOld.unit_price
newPrice = e._currentRowDataNew.unit_price
if lastPrice != newPrice
e._set.last_price.value = lastPrice
end if

create a xbasic function in onChange event for the price and insert this code (change field names as necessary) right under the declaration.
that will change as you change your price.
please note this will require a round trip to server ( while ajax id fast, still there is round trip).
so you can do with triggers or with this code. choice is yours.