How to use AppModeler to generate Delphi forms using Cached Updates
<HTML>
<TT>A beginner's question regarding AppModeler 6.1, Delphi 3, and Interbase
5.x...</TT>
<P><TT>While I am impressed with the amount of thought and work that has
gone into AppModeler, I have nonetheless been surprised to discover that
the Delphi application generated by AppModeler is not suitable for real-world
situations because of the "fly-away" problem afflicting newly-entered records.</TT>
<P><TT>When I enter a record on an AppModeler-generated Delphi form, the
record disappears ("flies away") immediately after it is posted. So, if
I enter ten records on a Delphi form and post each one, only the last record
is visible. In this situation, the only way to see all the newly-entered
records is to close the form and reopen it again.</TT>
<P><TT>I have been informed by Reid Roman on the newsgroup borland.public.delphi.database.sqlservers
that I should use "cached updates" to handle the data providing and resolving
process. Delphi Help says to do the following for a form based on a TQuery
dataset:</TT>
<P><TT>- Set the CachedUpdates property of the form's TQuery object to
TRUE.</TT>
<P><TT>- Create a TUpdateSQL object and point the TQuery's UpdateObject
property at it.</TT>
<P><TT>- Write event-handling code to apply the TUpdateSQL object at the
appropriate time (eg, when the form has been closed).</TT>
<P><TT>So now I've got to do two things:</TT>
<P><TT>- Create the Delphi objects and event-handling code to deal with
cached updates.</TT>
<P><TT>- Customize AppModeler's Delphi 3 templates so that these objects
and event-handling code are generated for all the tables in my database.
(This one has around 80 tables.)</TT>
<P><TT>As a beginner, I feel hesitant about modifying the Delphi 3 templates
that ship with AppModeler, especially when it would mean I'd have to worry
about all the subtleties of record-contention issues. I really find it
hard to believe that this level of customization is needed in order to
get AppModeler to create a usable Delphi front-end for an SQL database.</TT>
<P><TT>Since this kind of problem will eventually confront everyone who
tries to use AppModeler with Delphi for an SQL database, I hope there are
some standard solutions for this problem. Has anyone modified AppModeler's
Delphi 3 templates to deal with cached updates?</TT>
<P><TT>Any help would be greatly appreciated.</TT>
<P><TT>---------------------</TT>
<BR><TT>Scott Alexander</TT>
<BR><TT>scottx@bellsouth.net</TT>
<BR><TT>Jacksonville, Florida</TT></HTML>
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0 |
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Scott
10/15/1998 7:14:29 PM
sybase.powerdesigner.general
9408 articles. 
1 followers.
1 Replies
1133 Views
This sounds like a job for the guys in Tech Support. Submit this issue as a
bug to them and they will get the big guns aimed at it. I agree that this
is a problem with AppModeler for anyone using Delphi.
Good luck!
--
Michael F. Nicewarner [TeamPS]
mailto:mike.nicewarner@ibpinc.com
http://www.datamodel.org
Scott Alexander wrote in message <36264995.A82826A@bellsouth.net>...
A beginner's question regarding AppModeler 6.1, Delphi 3, and Interbase
5.x...
While I am impressed with the amount of thought and work that has gone
into AppModeler, I have nonetheless been surprised to discover that the
Delphi application generated by AppModeler is not suitable for real-world
situations because of the "fly-away" problem afflicting newly-entered
records.
When I enter a record on an AppModeler-generated Delphi form, the record
disappears ("flies away") immediately after it is posted. So, if I enter ten
records on a Delphi form and post each one, only the last record is visible.
In this situation, the only way to see all the newly-entered records is to
close the form and reopen it again.
I have been informed by Reid Roman on the newsgroup
borland.public.delphi.database.sqlservers that I should use "cached updates"
to handle the data providing and resolving process. Delphi Help says to do
the following for a form based on a TQuery dataset:
- Set the CachedUpdates property of the form's TQuery object to TRUE.
- Create a TUpdateSQL object and point the TQuery's UpdateObject
property at it.
- Write event-handling code to apply the TUpdateSQL object at the
appropriate time (eg, when the form has been closed).
So now I've got to do two things:
- Create the Delphi objects and event-handling code to deal with cached
updates.
- Customize AppModeler's Delphi 3 templates so that these objects and
event-handling code are generated for all the tables in my database. (This
one has around 80 tables.)
As a beginner, I feel hesitant about modifying the Delphi 3 templates
that ship with AppModeler, especially when it would mean I'd have to worry
about all the subtleties of record-contention issues. I really find it hard
to believe that this level of customization is needed in order to get
AppModeler to create a usable Delphi front-end for an SQL database.
Since this kind of problem will eventually confront everyone who tries
to use AppModeler with Delphi for an SQL database, I hope there are some
standard solutions for this problem. Has anyone modified AppModeler's Delphi
3 templates to deal with cached updates?
Any help would be greatly appreciated.
---------------------
Scott Alexander
scottx@bellsouth.net
Jacksonville, Florida
|
|
0 |
|
Michael
10/27/1998 9:44:42 PM
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