Обсуждение: RE: [INTERFACES] sequences

You might try placing the INSERT and SELECT CURRVAL into a transaction
block.-DEJ

> -----Original Message-----
> From:    Patrick Welche [SMTP:prlw1@newn.cam.ac.uk]
> Sent:    Thursday, April 29, 1999 1:05 PM
> To:    pgsql-interfaces@postgreSQL.org
> Subject:    [INTERFACES] sequences
> 
> After the interesting discussion on what is the safest way to have a
> unique
> "oid"-like value per row, I thought I would have a go, but from libpq++ I
> don't seem to be able to read the new sequence value:
> 
> Table    = person
> +----------------------------------+----------------------------------+---
> ----+
> |              Field               |              Type                |
> Length|
> +----------------------------------+----------------------------------+---
> ----+
> | id                               | int4 not null default nextval('p |
> 4 |
> | surname                          | text not null                    |
> var |
> | firstname                        | text not null                    |
> var |
> | email                            | text                             |
> var |
> | phone                            | text                             |
> var |
> | rfbdate                          | date                             |
> 4 |
> +----------------------------------+----------------------------------+---
> ----+
> Index:    person_id_key
> 
> The output from my test program is:
> 
> INSERT INTO person (surname,firstname,email,phone) VALUES
> ('Welche','Patrick','
> prlw1',null)
> SELECT currval('person_id_seq')
>    
>    Missing person id
> 
> and the relevant bit of code is:
> 
>         query<<"INSERT INTO person (surname,firstname,email,phone) VALUES
> ('"
>              <<a._surname<<"','"<<a._firstname<<"',"
>              <<ISNULL(a._email)<<','
>              <<ISNULL(a._phone)<<')'<<ends;         
>         s.send_query(query);   
>         query<<"SELECT currval('person_id_seq')"<<ends;
>         s.send_query(query);
>         if(s.Tuples()!=1)throw empty_result("Missing person id");
>         a.id(toid(s.GetValue(0,"currval")));
> 
> send_query prints the query and does a Exec(query). I suppose I don't
> understand the difference between doing things interactively in psql (the
> above INSERT and SELECT work then) and calling things from a program. Any
> tips?
> 
> Cheers,
> 
> Patrick

At 22:41 +0300 on 29/04/1999, Jackson, DeJuan wrote:


> You might try placing the INSERT and SELECT CURRVAL into a transaction
> block.

That shouldn't make a difference. Currval's scope is the entire session,
from the last call (or implicit call) to nextval to the next call.

Now, let's see if I understand right: The query works well in psql, but not
in a program? So let me ask you this - do you run the program, perhaps, as
a different user, such as the httpd or nobody user? If so, you need to
GRANT SELECT on the sequence to be able to use the currval function.

Herouth

--
Herouth Maoz, Internet developer.
Open University of Israel - Telem project
http://telem.openu.ac.il/~herutma

Herouth Maoz wrote:
> 
> At 22:41 +0300 on 29/04/1999, Jackson, DeJuan wrote:
> 
> 
> > You might try placing the INSERT and SELECT CURRVAL into a transaction
> > block.
> 
> That shouldn't make a difference. Currval's scope is the entire session,
> from the last call (or implicit call) to nextval to the next call.
> 
> Now, let's see if I understand right: The query works well in psql, but not
> in a program? So let me ask you this - do you run the program, perhaps, as
> a different user, such as the httpd or nobody user? If so, you need to
> GRANT SELECT on the sequence to be able to use the currval function.

Thank you!! That was it. (I had granted access to tables, not to sequences)

Cheers,

Patrick