As mentioned, if you are performing an INSERT/UPDATE or DELETE query and want to know the # of rows affected, you should use pg_affected_rows() instead of pg_num_rows().
However, you can also exploit postgres's RETURNING clause in your query to auto-select columns from the affected rows. This has the advantage of being able to tell not only how many rows a query affects, but exactly which rows those were, especially if you return a primary-key column.
For example:
<?php
// Example query. Let's say that this updates five rows in the source table.
$res = pg_query("Update foo set bar = 'new data' where foo.bar = 'old data' ");
pg_num_rows($res); // 0
pg_affected_rows($res); // 5
pg_fetch_all($res); // FALSE
// Same query, with a RETURNING clause.
$res = pg_query("Update foo set bar = 'new data' where foo.bar = 'old data' RETURNING foo.pkey");
pg_num_rows($res); // 5
pg_affected_rows($res); // 5
pg_fetch_all($res); // Multidimensional array corresponding to our affected rows & returned columns
?>
pg_num_rows
(PHP 4 >= 4.2.0, PHP 5, PHP 7, PHP 8)
pg_num_rows — Retourne le nombre de lignes PostgreSQL
Description
pg_num_rows(resource
$result): intpg_num_rows() retourne le nombre de lignes d'un résultat PostgreSQL.
Note:
Auparavant, cette fonction s'appelait pg_numrows().
Liste de paramètres
-
result -
Ressource résultat de requête PostgreSQL, retourné par pg_query(), pg_query_params() ou pg_execute() (entre autres).
Valeurs de retour
Le nombre de lignes dans le jeu de résultats. En cas d'erreur, -1 est retourné.
Exemples
Exemple #1 Exemple avec pg_num_rows()
<?php
$result = pg_query($conn, "SELECT 1");
$rows = pg_num_rows($result);
echo $rows . " ligne(s) retournée(s).\n";
?>
L'exemple ci-dessus va afficher :
1 ligne(s) retournée(s).
Voir aussi
- pg_num_fields() - Retourne le nombre de champ
- pg_affected_rows() - Retourne le nombre de lignes affectées
add a note
User Contributed Notes 3 notes
strata_ranger at hotmail dot com ¶
14 years ago
ElDiablo ¶
15 years ago
About preceding note, you shouldn't use pg_num_rows() for this.
You should have instead a look at pg_affected_rows().
francisco at natserv dot com ¶
16 years ago
Not sure why this documentation doesn't have the following note:
Note: Use pg_affected_rows() to get number of rows affected by INSERT, UPDATE and DELETE query.
Found on other resources. Adding here in case someone else is looking for the info.
