PHP 7.0.6 Released

pg_get_result

(PHP 4 >= 4.2.0, PHP 5, PHP 7)

pg_get_result Get asynchronous query result

Description

resource pg_get_result ([ resource $connection ] )

pg_get_result() gets the result resource from an asynchronous query executed by pg_send_query(), pg_send_query_params() or pg_send_execute().

pg_send_query() and the other asynchronous query functions can send multiple queries to a PostgreSQL server and pg_get_result() is used to get each query's results, one by one.

Parameters

connection

PostgreSQL database connection resource.

Return Values

The result resource, or FALSE if no more results are available.

Examples

Example #1 pg_get_result() example

<?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";
?>

The above example will output:

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

See Also

User Contributed Notes

william at 25thandClement dot com
11 years ago
There is no way to poll/wait for a notification to come in. You either have to enter a busy loop or sleep. Both options are horrible. It would be nice for PHP to provide access to PQsocket so one could select() on the socket connection. This is how it's done from C or Perl.
Ondej Bouda
7 months ago
It might seem that after calling pg_get_result() upon sending just a single query, the connection will not be busy. The correct way is, though, to call extra pg_get_result() in a loop until it returns false [1].

<?php
$conn
= pg_connect('...', PGSQL_CONNECT_FORCE_NEW);
for (
$i = 0; $i < 10000; $i++) {
   
$query = 'erroneous query';
    if (
pg_connection_busy($conn)) {
       
fprintf(STDERR, "Connection is busy\n");
        exit(
1);
    }
   
pg_send_query($conn, $query);
   
$res = pg_get_result($conn);
    if (
$res === false) {
       
fprintf(STDERR, "A result was expected\n");
        exit(
1);
    }

   
/* The following does not seem necessary for good queries, but is vital for erroneous queries.
       Commenting the loop out leads to this script fail with the "Connection is busy" error. */
   
while (pg_get_result($conn));

   
// result processing...
}
?>

See http://www.postgresql.org/message-id/flat/gtitqq$26l3$1@news.hub.org#gtitqq$26l3$1@news.hub.org and https://bugs.php.net/bug.php?id=52750 for detailed information.

[1] Or, even better, use an asynchronous connection since PHP 5.6.
gullevek at gullevek dot org
2 years ago
To have a a simple wait output with async queries you can use the pg_connection_busy command:

<?php
$dbh
= pg_connect("host=XXX user=XXX password=XXX dbname=XXX");
if (!
$dbh)
{
    print
"Failed to connect";
    exit;
}

$query = "SELECT pg_sleep(10)";
if (!
pg_connection_busy($dbh))
{
   
$sent = pg_send_query($dbh, $query);
    print
"Sent query, waiting: ";
    while (
pg_connection_busy($dbh)
    {
        print
".";
       
flush();
    }
   
$res = pg_get_result($dbh);
    print
"<br>"; // or \n
   
print "Result is: $res";
}

pg_close($dbh);
?>
Marko Tiikkaja
7 years ago
william at 25thandClement dot com said: "There is no way to poll/wait for a notification to come in. .."
Yes, there is. If there is a query in progress, pg_get_result() will block and return the result of that query when it's complete.
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