International PHP Conference Munich 2024

mysql_free_result

(PHP 4, PHP 5)

mysql_free_resultFree result memory

Avviso

Questa enstensione deprecata da PHP 5.5.0, e sarà rimossa in futuro. Al suo posto, usare l'estensione MySQLi o PDO_MySQL. Vedere anche la guida MySQL: scelta dell'API e le FAQ relative per ulteriori informazioni. Le alternative a questa funzione includono:

Descrizione

mysql_free_result(resource $result): bool

mysql_free_result() will free all memory associated with the result identifier result.

mysql_free_result() only needs to be called if you are concerned about how much memory is being used for queries that return large result sets. All associated result memory is automatically freed at the end of the script's execution.

Elenco dei parametri

result

The risultato resource che che viene calcolato. Questo risultato deriva dal una chiamata a mysql_query().

Valori restituiti

Restituisce true in caso di successo, false in caso di fallimento.

If a non-resource is used for the result, an error of level E_WARNING will be emitted. It's worth noting that mysql_query() only returns a resource for SELECT, SHOW, EXPLAIN, and DESCRIBE queries.

Esempi

Example #1 A mysql_free_result() example

<?php
$result
= mysql_query("SELECT id,email FROM people WHERE id = '42'");
if (!
$result) {
echo
'Could not run query: ' . mysql_error();
exit;
}
/* Use the result, assuming we're done with it afterwards */
$row = mysql_fetch_assoc($result);

/* Now we free up the result and continue on with our script */
mysql_free_result($result);

echo
$row['id'];
echo
$row['email'];
?>

Note

Nota:

Per la compatibilità all'indietro, i seguenti sinonimi (deprecati) possono essere utilizzati: mysql_freeresult()

Vedere anche:

add a note

User Contributed Notes 3 notes

up
15
webmaster at bluesting dot co dot za
13 years ago
mysql_query() also returns a resource for "OPTIMIZE TABLE" statements!
up
16
admin at ifyouwantblood dot de
16 years ago
yes this function may increase the memory usage if you use unbuffered querys and if you have not fetched all the data from mysql. in this case the mysql api has a problem: you want to free the result but do not want to close the connection. now mysql will only accept another query if all data has been fetched, so the api now must fetch the rest of the data when calling mysql_free_result().

so only use unbuffered querys if you fetch all the data (and need it).
up
-36
Anonymous
17 years ago
If you're seeing warnings like "Warning: Unknown: 6 result set(s) not freed. Use mysql_free_result to free result sets which were requested using mysql_query() in Unknown on line 0" and want to turn them off, set mysql.trace_mode = Off in your php.ini
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