Hi,
I'm just starded using ecpg and I have some problem with cursors.

I wrote this lines

exec sql begin declare section;
    char query[500];
    int CodImpianto;
    int Cod1;
    int Cod2;
    char Descr[100];
exec sql end declare section;
strcpy(query, "select ............");

exec sql connect db;

sub1()
{
    exec sql prepare stmtunimpianto from :query;
    exec sql declare CUR_UNIMPIANTO cursor for stmtunimpianto;
    .
    .
    .

    exec sql open CUR_UNIMPIANTO using :CodImpianto;
    exec sql fetch CUR_UNIMPIANTO into :CodImpianto, :Descr;
    .
    .

    exec sql close CUR_UNIMPIANTO;
    exec sql execute StmtUpdImpianti using :Cod1, :Descr, :Cod2;
    exec sql commit;
}

I call this routine a lot of time.
If I rem the commit all works fine but if I execute the commit the cursor was deleted and I receive some errors.

At open cursor : sqlca.sqlcode = -230 Invalid statement namei in line ......
at fetch           : NOTICE : PerformPortalFetch: portal "cur_unimpianto" not found

Please could anyone help me ?

thanks

regards
Maurizio Cauci
DREAMTECH di Cauci Maurizio
Via Ronchetti, 2 - 21013 Gallarate (VA)
www.dreamtech-it.com







Hi,
I'm just starded using ecpg and I have some problem 
with cursors.
 
I wrote this lines
 
exec sql begin declare section;
    char query[500];
    int CodImpianto;

    int Cod1;

    int Cod2;
    char Descr[100];

exec sql end declare section;
strcpy(query, "select ............");
 
exec sql connect db;
 
sub1()
{
    exec sql prepare stmtunimpianto 
from :query;
    exec sql declare CUR_UNIMPIANTO 
cursor for stmtunimpianto;
    .
    .
    .
 
    exec sql open CUR_UNIMPIANTO 
using :CodImpianto;
    exec sql fetch CUR_UNIMPIANTO 
into :CodImpianto, :Descr;

    .
    .
 
    exec sql close 
CUR_UNIMPIANTO;    exec sql execute StmtUpdImpianti 
using :Cod1, :Descr, :Cod2;
    exec sql commit;
}
 
I call this routine a lot of time.
If I rem the commit all works fine but if I execute 
the commit the cursor was deleted and I receive some errors.
 
At open cursor : sqlca.sqlcode = -230 Invalid 
statement namei in line ......
at 
fetch           : NOTICE 
: PerformPortalFetch: portal "cur_unimpianto" not found
 
Please could anyone help me ?
 
thanks
 
regards
Maurizio CauciDREAMTECH di Cauci 
MaurizioVia Ronchetti, 2 - 21013 Gallarate (VA)www.dreamtech-it.com
Tue, 7 Nov 2000 17:52:00 +0100
"Maurizio" <maurizio@dreamtech-it.com>
USE OF CURSORS IN ECPG
On Tue, Nov 07, 2000 at 05:52:00PM +0100, Maurizio wrote:
> I'm just starded using ecpg and I have some problem with cursors.
> ...
>     exec sql prepare stmtunimpianto from :query;
>     .
>     .
>     exec sql commit;
> ...
> If I rem the commit all works fine but if I execute the commit the cursor was deleted and I receive some errors.
> 
> At open cursor : sqlca.sqlcode = -230 Invalid statement namei in line ......
> at fetch           : NOTICE : PerformPortalFetch: portal "cur_unimpianto" not found

No surprise here as ending a transaction forces a deallocation of all
prepared statements. AFAIK that's what the standard says.

Michael

-- 
Michael Meskes
Michael@Fam-Meskes.De
Go SF 49ers! Go Rhein Fire!
Use Debian GNU/Linux! Use PostgreSQL!

Wed, 8 Nov 2000 12:39:42 +0100
Michael Meskes <meskes@postgresql.org>
Re: USE OF CURSORS IN ECPG
But, how can I do ?
I have to recall the same routine many times. I tried to prepare and declare
the cursor inside the routine but when I compile with ecpg I receive the
error Cursor already defined.

Maurizio


.
----- Original Message -----
From: "Michael Meskes" <meskes@postgresql.org>
To: "Maurizio" <maurizio@dreamtech-it.com>
Cc: <pgsql-interfaces@postgresql.org>
Sent: Wednesday, November 08, 2000 12:39 PM
Subject: Re: [INTERFACES] USE OF CURSORS IN ECPG


> On Tue, Nov 07, 2000 at 05:52:00PM +0100, Maurizio wrote:
> > I'm just starded using ecpg and I have some problem with cursors.
> > ...
> >     exec sql prepare stmtunimpianto from :query;
> >     .
> >     .
> >     exec sql commit;
> > ...
> > If I rem the commit all works fine but if I execute the commit the
cursor was deleted and I receive some errors.
> >
> > At open cursor : sqlca.sqlcode = -230 Invalid statement namei in line
......
> > at fetch           : NOTICE : PerformPortalFetch: portal
"cur_unimpianto" not found
>
> No surprise here as ending a transaction forces a deallocation of all
> prepared statements. AFAIK that's what the standard says.
>
> Michael
>
> --
> Michael Meskes
> Michael@Fam-Meskes.De
> Go SF 49ers! Go Rhein Fire!
> Use Debian GNU/Linux! Use PostgreSQL!


Thu, 9 Nov 2000 14:49:29 +0100
"Maurizio" <maurizio.c@libero.it>
Re: [INTERFACES] USE OF CURSORS IN ECPG
Maurizio wrote:

> But, how can I do ?
> I have to recall the same routine many times. I tried to prepare and declare
> the cursor inside the routine but when I compile with ecpg I receive the
> error Cursor already defined.

you should drop the cursor (exec sql close name;)
But there is trouble ahead (believe me - see below)

> Maurizioan

------------
(Oh, I misunderstood, if you get into trouble with transactions (waiting for
you ;-() you might consider the following lines)
------------
You certainly should disable autocommit!
  exec sql set autocommit to off;
otherwise you have no control over when a transaction starts and whether this
succeded.
Then at the start of your SubProgram do
  bool my_transaction;
  exec sql begin work;
  my_transaction=!sqlca.sqlcode;

at the end:
  if (my_transaction) exec sql commit work;

This should give you an idea on how to accomplish it. If not feel free to ask
me.

But (sigh) you need my NOTICE to sqlca patch applied. It's not in 7.0 but in
7.1! I don't know any other way (I'll attach the patch)

Christof

PS: You might consider applying the patch for (update where not_found) -> 100
and the cache which doubles ecpg's speed.
Fri, 10 Nov 2000 11:52:48 +0100
Christof Petig <christof.petig@wtal.de>
Re: Re: [INTERFACES] USE OF CURSORS IN ECPG