Trying to execute several queries involving temp tables in a PHP script

Started by Alexander Farberalmost 14 years ago6 messagesgeneral
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#1Alexander Farber
alexander.farber@gmail.com

Hello fello PostgreSQL users,

with PHP 5.3.3 and PostgreSQL 8.4.11
(and a pgbouncer, but I've tried without it too)
I'm trying to execute several SQL queries
with 2 temp tables (listed below) and then use
the result of a final join to construct a JSON array.

Unfortunately my script using prepare/execute
(and I've tried query() too) fails with PHP error:
"cannot insert multiple commands into a prepared statement".

And when I split my statements into multiple
prepare()/execute() or query() calls,
then the temp. tables aren't found anymore.

Any ideas please on how to handle this situation
in PHP scripts, do I really have to encapsulate
my calls into a pl/PgSQL function?

More details on my query and setup:
http://stackoverflow.com/questions/11010784/error-cannot-insert-multiple-commands-into-a-prepared-statement

And below is my PHP code:

try {
$options = array(PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION);
$db = new PDO(sprintf('pgsql:host=%s port=%u; dbname=%s',
DBHOST, DBPORT, DBNAME), DBUSER, DBPASS, $options);

$sth = $db->prepare("
start transaction;
create temporary table temp_ids (id varchar not null) on
commit drop;
insert into temp_ids (id)
select id
from pref_money
where yw = to_char(current_timestamp - interval '1
week', 'IYYY-IW')
order by money
desc limit 10;

create temporary table temp_rids (rid integer not null) on
commit drop;
insert into temp_rids (rid)
select rid
from pref_cards
where stamp > now() - interval '1 day' and
id in (select id from temp_ids) and
bid = 'Misere' and
trix > 0;

SELECT r.rid, r.cards, to_char(r.stamp, 'DD.MM.YYYY
HH24:MI') as day,
c.bid, c.trix, c.pos, c.money, c.last_ip, c.quit,
u.id, u.first_name, u.avatar, u.female, u.city,
u.vip > CURRENT_DATE as vip
FROM pref_rounds r, pref_cards c, pref_users u
WHERE u.id = c.id and
r.rid = c.rid and
r.rid in (select rid from temp_rids)
order by rid, pos;
commit;
");
$sth->execute();
while ($row = $sth->fetch(PDO::FETCH_ASSOC)) {
# construct a JSON array of objects
}
} catch (Exception $e) {
exit('Database problem: ' . $e->getMessage());
}

Thank you
Alex

#2Alban Hertroys
haramrae@gmail.com
In reply to: Alexander Farber (#1)
Re: Trying to execute several queries involving temp tables in a PHP script

On 13 June 2012 15:12, Alexander Farber <alexander.farber@gmail.com> wrote:

And when I split my statements into multiple
prepare()/execute() or query() calls,
then the temp. tables aren't found anymore.

Did you remember to wrap them in a transaction like you did in your
prepared statement?

--
If you can't see the forest for the trees,
Cut the trees and you'll see there is no forest.

#3Misa Simic
misa.simic@gmail.com
In reply to: Alexander Farber (#1)
Re: Trying to execute several queries involving temp tables in a PHP script

Hi Alexander,

I think you can have all in one query, without temp tables:

SELECT r.rid, r.cards, to_char(r.stamp, 'DD.MM.YYYY
HH24:MI') as day,
c.bid, c.trix, c.pos, c.money, c.last_ip, c.quit,
u.id, u.first_name, u.avatar, u.female, u.city,
u.vip > CURRENT_DATE as vip
FROM pref_rounds r, pref_cards c, pref_users u
WHERE u.id = c.id and
r.rid = c.rid and
r.rid in (

select rid
from pref_cards
where stamp > now() - interval '1 day' and
id in (
select id
from pref_money
where yw = to_char(current_timestamp - interval '1
week', 'IYYY-IW')
order by money
desc limit 10

) and
bid = 'Misere' and
trix > 0

)
order by rid, pos;

2012/6/13 Alexander Farber <alexander.farber@gmail.com>

Show quoted text

Hello fello PostgreSQL users,

with PHP 5.3.3 and PostgreSQL 8.4.11
(and a pgbouncer, but I've tried without it too)
I'm trying to execute several SQL queries
with 2 temp tables (listed below) and then use
the result of a final join to construct a JSON array.

Unfortunately my script using prepare/execute
(and I've tried query() too) fails with PHP error:
"cannot insert multiple commands into a prepared statement".

And when I split my statements into multiple
prepare()/execute() or query() calls,
then the temp. tables aren't found anymore.

Any ideas please on how to handle this situation
in PHP scripts, do I really have to encapsulate
my calls into a pl/PgSQL function?

More details on my query and setup:

http://stackoverflow.com/questions/11010784/error-cannot-insert-multiple-commands-into-a-prepared-statement

And below is my PHP code:

try {
$options = array(PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION);
$db = new PDO(sprintf('pgsql:host=%s port=%u; dbname=%s',
DBHOST, DBPORT, DBNAME), DBUSER, DBPASS, $options);

$sth = $db->prepare("
start transaction;
create temporary table temp_ids (id varchar not null) on
commit drop;
insert into temp_ids (id)
select id
from pref_money
where yw = to_char(current_timestamp - interval '1
week', 'IYYY-IW')
order by money
desc limit 10;

create temporary table temp_rids (rid integer not null) on
commit drop;
insert into temp_rids (rid)
select rid
from pref_cards
where stamp > now() - interval '1 day' and
id in (select id from temp_ids) and
bid = 'Misere' and
trix > 0;

SELECT r.rid, r.cards, to_char(r.stamp, 'DD.MM.YYYY
HH24:MI') as day,
c.bid, c.trix, c.pos, c.money, c.last_ip, c.quit,
u.id, u.first_name, u.avatar, u.female, u.city,
u.vip > CURRENT_DATE as vip
FROM pref_rounds r, pref_cards c, pref_users u
WHERE u.id = c.id and
r.rid = c.rid and
r.rid in (select rid from temp_rids)
order by rid, pos;
commit;
");
$sth->execute();
while ($row = $sth->fetch(PDO::FETCH_ASSOC)) {
# construct a JSON array of objects
}
} catch (Exception $e) {
exit('Database problem: ' . $e->getMessage());
}

Thank you
Alex

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#4Leif B. Kristensen
leif@solumslekt.org
In reply to: Alexander Farber (#1)
Re: Trying to execute several queries involving temp tables in a PHP script

Onsdag 13. juni 2012 15.12.33 skrev Alexander Farber :

Any ideas please on how to handle this situation
in PHP scripts, do I really have to encapsulate
my calls into a pl/PgSQL function?

I believe that Misa Simic's idea that you can do it all in a single query
without temp tables is correct. But anyway, it's always a good idea to
encapsulate multiple interdependent queries in a single pl/pgsql function. I
tend to keep my PHP code as simple as possible, and do most of the work inside
the database.

regards, Leif
http://code.google.com/p/yggdrasil-genealogy/

#5Misa Simic
misa.simic@gmail.com
In reply to: Leif B. Kristensen (#4)
Re: Trying to execute several queries involving temp tables in a PHP script

I agree with approach to have all in functions... In that case there would
not be a problem with temp tables because of inside 1 transaction they
would work...

suggestion was just to solve problem from php... what would be achiavable
just trough 1 query, or to use PDO and then:

$dbh->beginTransaction();
$dbh->exec(query1);
$dbh->exec(query2);
$dbh->exec(query3);
$dbh->commit();

Kind Regards,

Misa

2012/6/13 Leif Biberg Kristensen <leif@solumslekt.org>

Show quoted text

Onsdag 13. juni 2012 15.12.33 skrev Alexander Farber :

Any ideas please on how to handle this situation
in PHP scripts, do I really have to encapsulate
my calls into a pl/PgSQL function?

I believe that Misa Simic's idea that you can do it all in a single query
without temp tables is correct. But anyway, it's always a good idea to
encapsulate multiple interdependent queries in a single pl/pgsql function.
I
tend to keep my PHP code as simple as possible, and do most of the work
inside
the database.

regards, Leif
http://code.google.com/p/yggdrasil-genealogy/

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#6Alexander Farber
alexander.farber@gmail.com
In reply to: Misa Simic (#3)
Re: Trying to execute several queries involving temp tables in a PHP script

Thank you Misa, the without-temp-tables query has worked flawlessly.

Show quoted text

On Wed, Jun 13, 2012 at 5:01 PM, Misa Simic <misa.simic@gmail.com> wrote:

I think you can have all in one query, without temp tables:

 SELECT r.rid, r.cards, to_char(r.stamp, 'DD.MM.YYYY
HH24:MI') as day,
                   c.bid, c.trix, c.pos, c.money, c.last_ip, c.quit,
                   u.id, u.first_name, u.avatar, u.female, u.city,
u.vip > CURRENT_DATE as vip
                   FROM pref_rounds r, pref_cards c, pref_users u
                   WHERE u.id = c.id and
                       r.rid = c.rid and
                       r.rid in (

 select rid
                   from pref_cards
                   where stamp > now() - interval '1 day' and
                   id in (
 select id
                   from pref_money
                   where yw = to_char(current_timestamp - interval '1
week', 'IYYY-IW')
                   order by money
                   desc limit 10

) and
                   bid = 'Misere' and
                   trix > 0

)
                   order by rid, pos;