----- Original Message -----
From: "Helen Borrie" <helebor@...>
To: <IBObjects@yahoogroups.com>
Sent: Tuesday, September 17, 2002 6:01 PM
Subject: Re: [IBO] I get dbhandle always 1 (ERR Handling)


> At 09:36 AM 17-09-02 +0300, you wrote:
> >Hi Jason.
> >
> > I'm writing a finance application and it's multiuser. I'm trying to
> > get meaningful err messages
> >from the running SP's ( I don't use Triggers much I like controllig the
> >events). IB's event option
> >is not suitable for me becouse you can only get the messages when the
> >transaction committed, this is
> >too late for me.
>
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Burak:Start a transaction and create some event, you'll not get the event's till you commit the
transaction.
I tried this very much.
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> No, this is not correct.
>
> In your SP or trigger you catch an exception using an EXCEPTION statement
> (using a custom exception which you have previously declared in your
> metadata with a message string of up to 78 bytes).
>
> Then you use ON EXCEPTION GDSCODE (for a specific database exception) or ON
> EXCEPTION MyException to handle it. When an exception occurs, control
> always passed into this block and you can do whatever you need, including
> fire an event if you want.
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Burak:
Can you give me a SP example that handling User Defined Exception with ON EXCEPTION statement??

I want to handle exception and see the message at client side.. for example
create main procedure XXXX
begin
execute procedure y
execute procedure z
execute procedure g
(an exception occured
1 I have to see the exception at client side
2 procedure L must run after the exception)
execute procedure L
execute procedure d
end
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>
> In your handler you can either "silence" the exception (do something about
> the bad data) and then, at the end of the block, control will pass back to
> the statement following the one where the exception occurred; or you can
> make the procedure terminate. If the exception which you caught was a
> custom exception, the exception message which you defined returns to the
> client in the Error Status Vector. IBO provides access to everything in
> this array in several ways, including the OnError events of all TIB_ and
> TIBO components.
> You also have the option of firing a database event upon catching an exception.
>
> There is a TI sheet on the TechInfo page about exceptionhandling.
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Burak: where is this TI sheet on firebirdsql.org or ibphoenix.com or ibobjects site????
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>
> >When a user get's in a module a transaction starts separetaly and when the
> >job is
> >done the transaction commits. There are many SP's running in a
> >transaction. I have to get the
> >messages when the exception occures. I can't use exceptions also becouse
> >it crashes the SP
> >execution
>
> What do you mean by "crashes the SP execution"?
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Burak:I mean if an user defined exception occurs SP stops execution and exits the SP when not
handled.
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> >( And I can't handle the exception from client side, If there is a chance
> >to do it please
> >inform me).

>
> Oh yes, oh yes. If you haven't explored IBO's capabilities for supporting
> and expanding on the server side exception-handling features then you have
> missed something wonderful. :-))
>
> >Most of the time I call one SP at a time and that SP call's many sp's
> >internally. One of
> >The most important reaseon why I need this messages, if an exception
> >occurs I have to roll back the
> >SP's for data integritiy.
>
> That is EXACTLY why PSQL has exception-handling and why IBO takes so much
> care to surface it for you.
>
>
> >Now waht will I do with database handle??
> >
> > I get the transaction handle when the transaction starts. I'm trying
> > to get the dbhandle when my
> >main connection connects. Wit these I'll get a two field unique (I
> >couldn't test unique becouse I
> >can't get dbhandle yet) index. I'll send these two field to my all SP's
> >and when a exception occurs.
> >An another SP will write the required information to a table with this
> >informaiton. After execution
> >of a SP I'll read the table, if there are records about these two field,
> >I'll decide what to do
> >depending to the exception states.
> >
> >This is why I need dbhandle.
>
> No, you don't need the dbhandle, nor the transaction handle. Just use what
> is already well encapsulated for you in that marvellous triangle: server,
> client and IBO.
>
> Helen

>
>