Handling an exception in a superclass...

Question

Hi,
Why not have a method at the superclass level, called ExecSQL(), that
internally does the following:
begin
self.OnExecSQL();
exception
when e:Whatever do
end;
In that way all your code in the hierarchy that is in OnExecSQL() is within
the exception block.
Tim Sawyer
PanCredit
Leeds, UK.
From: Gabriel Akos <[email protected]>
Reply-To: Gabriel Akos <[email protected]>
To: [email protected], [email protected]
Subject: Handling an exception in a superclass...
Date: Mon, 17 May 1999 17:26:06 +0200
Hi!
I have the following problem:
1. I have a class, name SQLManager
2. I have a method, ExecSQL
3. In method ExecSQL I do some SQL, occasionally it's loosing the
connection to the DB, gets an
exception, reasoncode 201 (If my memory is correct)
4. I have some subclasses of SQLManager, which override ExecSQL, and do
some SQL stuff in it.
Question: Is it possible to handle the specific exception in the
superclass, and do the reconnect?
And probably let the subclass execute the ExecSQL again?
Or has anybody better ideas of organizing these things?
TIA, best regards,
Akos Gabriel
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Answer 1

Hi,
Yes you can : it is an architectural problem.
You must divide the work into 2 methods : one on the generic level and one
on the concrete level.
The generic level will manage the cinematic : it could be ExecSql. In the
ExecSql method you can call a DoExecSql method which can be overridden by
the developers and contain the sql statement. Then, the ExecSql method can
manage the reconnect using DBSession.Reconnect before the call of the
DoExecSql if the DBSession.IsConnected = FALSE. You can also manage a While
with a limited number of retries if you catch the exception from the
DoExecSql method.
Just be aware that when you will reconnect to the database, you will loose
the statements you could have cached with your DBSession.
Hope this helps,
Daniel Nguyen
Freelance Forte Consultant
Url : http://perso.club-internet.fr/dnguyen/
Gabriel Akos a &eacute;crit:
Hi!
I have the following problem:
1. I have a class, name SQLManager
2. I have a method, ExecSQL
3. In method ExecSQL I do some SQL, occasionally it's loosing the
connection to the DB, gets an
exception, reasoncode 201 (If my memory is correct)
4. I have some subclasses of SQLManager, which override ExecSQL, and do
some SQL stuff in it.
Question: Is it possible to handle the specific exception in the
superclass, and do the reconnect?
And probably let the subclass execute the ExecSQL again?
Or has anybody better ideas of organizing these things?
TIA, best regards,
Akos Gabriel
To unsubscribe, email '[email protected]' with
'unsubscribe forte-users' as the body of the message.
Searchable thread archive <URL:http://pinehurst.sageit.com/listarchive/>-
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'unsubscribe forte-users' as the body of the message.
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