pg_fetch_array

(PHP 4, PHP 5, PHP 7, PHP 8)

pg_fetch_array — Carica una tupla in un array

Descrizione

pg_fetch_array(resource $result, int $tupla = ?, int $tipo_risultato = ?): array

pg_fetch_array() restituisce un array che corrisponde alla riga caricata (tuple/record). Restituisce false se non ci sono più righe.

pg_fetch_array() è una versione estesa di pg_fetch_row(). Oltre a salvare i dati in un array con indici numerici, li salva pure in un array associativo, utilizzando i nomi dei campi come chiave.

tupla è il numero della riga (record) che deve essere caricata. La prima riga è la 0.

tipo_risultato è un parametro opzionale che controlla come il risultato viene restituito. result_type è una costante e può assumere i seguenti valori: PGSQL_ASSOC, PGSQL_NUM, e PGSQL_BOTH. pg_fetch_array() restituisce un array associativo con il nome del campo come chiave con PGSQL_ASSOC, oppure l'indice del campo con PGSQL_NUM o entrambi con PGSQL_BOTH. Il default è PGSQL_BOTH.

Nota:
tipo_risultato è stato aggiunto nel PHP 4.0.

pg_fetch_array() NON è più lento di pg_fetch_row(), inoltre è più facile da usare.

Example #1 PostgreSQL fetch array

<?php 
$conn = pg_pconnect ("dbname=editori");
if (!$conn) {
    echo "Si è verificato un errore.\n";
    exit;
}

$risultato = pg_query ($conn, "SELECT * FROM autori");
if (!$risultato) {
    echo "Si è verificato un errore.\n";
    exit;
}

$arr = pg_fetch_array ($risultato, 0, PGSQL_NUM);
echo $arr[0] . " <- array\n";

$arr = pg_fetch_array ($risultato, 1, PGSQL_ASSOC);
echo $arr["autore"] . " <- array\n";
?>

Vedere anche pg_fetch_row(), pg_fetch_object() e pg_fetch_result().

Nota:
Dalla versione 4.1.0, tupla è opzionale. La chiamata a pg_fetch_array() incrementa di 1 il puntatore alle tuple.

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User Contributed Notes 12 notes

down

mkb at ele dot uri dot edu ¶

23 years ago


The column names if you use PGSQL_ASSOC or PGSQL_BOTH are always in lowercase, no matter what the name is in the database or in the query.

down

jesse at sokieserv dot dhs dot org ¶

23 years ago


As of PHP 4.1.0, you can now use code such as the following to iterate through a result set:



$conn = pg_connect("host=localhost dbname=whatever");

$result = pg_exec($conn, "select * from table");

while ($row = pg_fetch_array($result))

{

     echo "data: ".$row["data"];

}



Can be a nice little time saver, PHP with MySQL has supported this for a while but I'm glad to see it extended to PostgreSQL...

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gherson at snet dot net ¶

23 years ago


PGSQL_BOTH is the default, meaning your array size will be doubled.  

If you specify this field (result type), include no quotes around it or you won't get any data, not even an error.  

Here's my wrapper function:

function SQL_fetch_array($result_ndx, $row, $result_type=PGSQL_ASSOC) { 

   return pg_fetch_array($result_ndx, $row, $result_type);

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gherson at snet dot net ¶

23 years ago


In addition to returning "false if there are no more rows", pg_fetch_array will also trigger an E_WARNING.  You can temporarily turn that error reporting level off and suck out all your data like so:



<?php

$errRptLvl = error_reporting(); 

error_reporting($errRptLvl & ~(E_WARNING));

       

list($i,$j)=array(0,0); 

while ($selection[$i++] = $this->fetchArray($j++)); // (fetchArray is a pg_fetch_array wrapper.)

error_reporting($errRptLvl); // Restore error reporting level.

unset($selection[$i-1]); // Delete the last, empty row.

return $selection;

?>

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strata_ranger at hotmail dot com ¶

15 years ago


Note that when using PGSQL_BOTH, numerically and associatively indexed fields are separate variables and treated as such:

<?php
$res = pg_query("Select 'foo' as bar");

$data = pg_fetch_array($res, 0, PGSQL_BOTH);

var_dump($data);
// Array(2)
// {
//   [0] => string(3) "foo"
//   ["bar"] => string(3) "foo"
// }

// This won't affect $data['bar']
$data[0] = 'bar';

var_dump($data);
// Array(2)
// {
//   [0] => string(3) "bar"
//   ["bar"] => string(3) "foo"
// }
?>

If you want to have reference binding between your numeric and associative indexes, you'll have to establish that yourself:

<?php

$result = pg_query("Select 'foo' as bar");

$data = pg_fetch_row($result);

// Establish references between column name/number
$from = $data;
foreach($from as $cx => $value)
{
    $key = pg_field_name($result, $cx);
    if (is_string($key)) $data[$key] =& $data[$cx];
}

var_dump($data);
// Array(2)
// {
//   [0] => &string(3) "foo"
//   ["bar"] => &string(3) "foo"
// }
// Note the reference binding between $data[0] and $data['bar']

$data[0] = 'baz';

var_dump($data);
// Array(2)
// {
//   [0] => &string(3) "baz"
//   ["bar"] => &string(3) "baz"
// }

?>

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akm at e-nterart dot pl ¶

21 years ago


(Timesaver) Be aware of the fact that keys in array returned by this function are (well, at least as of 4.2.3) of the same case as SQL column names (e.g. if your column name is ID then key name is also ID, not id or Id), and the keys in associative array are CASE SENSITIVE!!! So don't be surprised if you get unexpected results. Double check SQL column names and the key names.

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devnull ¶

19 years ago


In response to eth0's comment below about SELECT'ing from two tables where the tables have columns with the same names, you can get around this problem like this:

"SELECT table1.foo AS foo1, table2.foo AS foo2 FROM table1, table2"

In the associative array returned, the keys will be "foo1" and "foo2".

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-1

anonymous ¶

19 years ago


Hopefully most people realize this on their own, but the examples below where people tried to get creative with getting numerical or associative (not both) keys in the result are rather pointless. See the pg_fetch_assoc() and pg_fetch_row() for the built in functions that do this automatically. It's generally a better idea to use one of these other functions unless you *need* to access fields by both collumn name *and* index.

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-1

enyo at www.red-link.com ¶

21 years ago


Just because it is not really clear how to specify the result type, I poste this message.

I wrote a wrapper function which looks like this:

<?php
    function db_fetch_array ($result, $row = NULL, $result_type = PGSQL_ASSOC)
    {
        $return = @pg_fetch_array ($result, $row, $result_type);
        return $return;
    }
?>

I think this way it is quite comfortable to get the arrays you want.

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-1

elliot at nospam dot rightnowtech dot com ¶

23 years ago


Just remember when you 'or die' to close your table(s) or you may get a confused look from non-internet explorer users.

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-2

eth0 at fins ¶

23 years ago


Please remember that if you have for example a table Customers with "cust_ID", "name" and "address" and another table Users with "u_ID","name" and "other" and then you SELECT WHERE cust_ID=u_ID then you'll get in the result array ONLY ONE "name" field, precisely the last one resulted from the select!!!

down

-3

Dave O ¶

19 years ago


I found this out through help from the mailing lists.  If you need to reset the internal counter, use the pg_result_seek, similar to:

pg_result_seek($result, 0)

...plagiarized from the comment on the function's doc page.

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