pg_send_query_params
If you open a second connection with PGSQL_CONNECT_FORCE_NEW and send a second query to the second connection, it will still block on the first one.
pg_send_query
(PHP 4 >= 4.2.0, PHP 5)
pg_send_query — Envia uma consulta (query) assincrona
Descrição
bool pg_send_query
( resource
$connection
, string $query
)
bool pg_send_query
( string
$query
)
pg_send_query() envia uma consulta (query) assíncrona para
connection. Diferente de
pg_query(), ela pode enviar consultas múltiplas para o
PostgreSQL e carregar os resultados, um por um, usando
pg_get_result(). A execução do script não é bloqueada
enquanto as consultas estão sendo executadas. Use
pg_connection_busy() para checar se a conexão está
ocupada. (por exemplo, se uma consulta está sendo executada). A consulta pode
ser cancelada chamando pg_cancel_query().
Apesar de ser possível enviar multiplas consultas de uma vez, você não pode enviar múltiplas consultas para uma conexão ocupada. Se a consulta é enviada enquando a conexão está ocupada ela espera até que a última cosulta seja finalizada e descarta todos os resultados.
Exemplo #1 Asynchronous Queries
<?php
$dbconn = pg_connect("dbname=publisher") or die("Could not connect");
if (!pg_connection_busy($dbconn)) {
pg_send_query($dbconn,"select * from authors; select count(*) from authors;");
}
$res1 = pg_get_result($dbconn);
echo "First call to pg_get_result(): $res1\n";
$rows1 = pg_num_rows($res1);
echo "$res1 has $rows1 records\n\n";
$res2 = pg_get_result($dbconn);
echo "second call to pg_get_result(): $res2\n";
$rows2 = pg_num_rows($res2);
echo "$res2 has $rows2 records\n";
?>
O exemplo acima deve mostrar a seguinte saída:
first call to pg_get_result(): Resource id #3 Resource id #3 has 3 records second call to pg_get_result(): Resource id #4 Resource id #4 has 1 records
Veja também pg_query(), pg_cancel_query(), pg_get_result() e pg_connection_busy().
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User Contributed Notes
pg_send_query - [7 notes]
Cstdenis ¶
7 months ago
moodsey211 at gmail dot com ¶
2 years ago
pg_send_query would not stop your script from executing but it would stop the script from exiting.
Example:
<?php
$con = pg_connect('dbname=payroll');
pg_send_query('SELECT process_payroll()'); // Where process_payroll is a super long process
?>
You would still need to wait for the query to finish before the any display would be sent to the browser. And surprisingly, unlike pg_query this script would not generate the Maximum execution time error.
rw burgholzer is name at deq dot virginia dot gov ¶
3 years ago
Regarding the failure to process them all now, then retrieve the results later, I found that all queries would return successfully if I added a further condition to your while loop in the "stack_query()" method.
By adding:
&& (pg_transaction_status($conn) === PGSQL_TRANSACTION_IDLE ) )
Every query executed with no errors.
<?php
$conn = pg_connect("dbname=dbname host=localhost user=psql ");
if ($conn === FALSE)
exit("Can't connect to db");
$q = array();
// send some queries
foreach (range(0, 50) as $i)
stack_query($q, $conn, "SELECT 'query $i' AS str;");
// receive them
while (true)
{
$left = stack_query($q, $conn);
echo "$left left... ";
$result = pg_get_result($conn);
if ($left == 0 && $result === FALSE)
break;
$row = pg_fetch_assoc($result);
// depending on race conditions, you wont get all your original queries here.
echo "got $row[str]\n";
}
function stack_query(&$queries, $conn, $sql = FALSE)
{
if ($sql !== FALSE)
$queries[] = $sql;
while (count($queries) && !pg_connection_busy($conn) && (pg_transaction_status($conn) === PGSQL_TRANSACTION_IDLE ) )
pg_send_query($conn, array_shift($queries));
return count($queries) + (pg_connection_busy($conn) ? 1 : 0);
}
?>
vincentdephily ¶
7 years ago
Note that if you send a query without calling pg_get_result() for the previous one (supposing it has finished and the connection is not busy), the previous query will get discarded.
See for yourself (tested on php4.4.0, postgres8.0.4, Linux/FreeBSD) :
<?
$conn = pg_connect("dbname=template1 host=localhost user=pgsql");
if ($conn === FALSE)
exit("Can't connect to db");
$q = array();
// send some queries
foreach (range(0, 500) as $i)
stack_query($q, $conn, "SELECT 'query $i' AS str;");
// receive them
while (true)
{
$left = stack_query($q, $conn);
echo "$left left... ";
$result = pg_get_result($conn);
if ($left == 0 && $result === FALSE)
break;
$row = pg_fetch_assoc($result);
// depending on race conditions, you wont get all your original queries here.
echo "got $row[str]\n";
}
function stack_query(&$queries, $conn, $sql = FALSE)
{
if ($sql !== FALSE)
$queries[] = $sql;
while (count($queries) && !pg_connection_busy($conn))
pg_send_query($conn, array_shift($queries));
return count($queries) + (pg_connection_busy($conn) ? 1 : 0);
}
?>
You will have to write a higher level of abstraction if you want a "send all queries now, receive them later" behaviour.
Likeyouover others at hotmail dot com ¶
9 years ago
<?php
// --------- OPEN CONN ---
$conn = pg_connect("host='127.0.0.1' dbname='test' user='usertest' password='passtest'");
// --------- OPEN FILE ---
$fp = fopen('logo.gif', "r");
$buffer = fread($fp, filesize('logo.gif'));
fclose($fp);
// --------- CREATE - INSERT OID ---
pg_exec($conn, "begin");
$oid = pg_locreate($conn);
$rs = pg_exec($conn,"INSERT INTO test(tipo, images) VALUES('A1', $oid);");
$handle = pg_loopen ($conn, $oid, "w");
pg_lowrite ($handle, $buffer);
pg_loclose ($handle);
pg_exec($conn, "commit");
// --------- OPEN - INSERT OID ---
$rs = pg_exec($conn, "SELECT images FROM test WHERE tipo = 'A1';");
$row = pg_fetch_row($rs, 0);
pg_exec($conn, "begin");
$loid = pg_loopen($conn, $row[0], "r");
header("Content-type: image/gif");
pg_loreadall($loid);
pg_loclose($loid);
pg_exec ($conn, "commit");
// --------- UNLINK OID ---
pg_exec($conn, "begin");
$loid = $row[0];
pg_lounlink($conn, $loid);
pg_exec ($conn, "commit");
// --------- DELETE OID ---
pg_exec($conn, "DELETE FROM test WHERE tipo = 'A1';");
// --------- CLOSE CONN ---
pg_close();
?>
Mikewithme at yahoo dot com ¶
9 years ago
Due to a bug, OLD API does not available with PHP 4.2.0 and 4.2.1.
PHP 4.2.2 will support OLD API again and will be kept long enough.
New API will be available PHP 4.2.0 to later versions.
yohgaki at php dot net
19-Jun-2002 04:00
Due to a bug, PHP 4.2.0 and 4.2.1 does not support pg_lo_import() old API. It's fixed in PHP 4.2.2.
BTW, new API will be always available from PHP 4.2.0 to later versions. Older API will be kept long enough, also.
ceco at noxis dot net
15-May-2002 09:08
it works for me (php-4.2.1)
not like this
int pg_lo_import ( string pathname [, resource connection])
but
int pg_lo_import ( resource connection, string pathname )
don't know the reason
Ron Howard ¶
10 years ago
If there is an error in one of your queries, the queries following it will not get executed, and there will *not* be an error message displayed. The only way I can think of to determine if an SQL error happened is to use pg_trace.
Example:
pg_send_query($connection,
"SELECT id FROM users;
SELECT * FROM customers;
[INVALID-SQL-STATEMENT];
SELECT name FROM countries;");
while ($result = pg_get_result($connection))
$results[] = $result;
The $results array will only have two items in it.