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PDO->exec()

(no version information, might be only in CVS)

PDO->exec() --  Execute an SQL statement and return the number of affected rows

Descrizione

class PDO {

int exec ( string statement )

}

PDO->exec() executes an SQL statement in a single function call, returning the number of rows affected by the statement.

PDO->exec() does not return results from a SELECT statement. For a SELECT statement that you only need to issue once during your program, consider issuing PDO->query(). For a statement that you need to issue multiple times, prepare a PDOStatement object with PDO->prepare() and issue the statement with PDOStatement->execute().

Elenco dei parametri

statement

The SQL statement to prepare and execute.

Valori restituiti

PDO->exec() returns the number of rows that were modified or deleted by the SQL statement you issued. If no rows were affected, PDO->exec() returns 0.

Avvertimento

Questa funzione può restituire il Booleano FALSE, ma può anche restituire un valore non-Booleano valutato come FALSE, come ad esempio 0 o "". Per favore fare riferimento alla sezione Booleans per maggiori informazioni. Usare l'operatore === per controllare il valore restituito da questa funzione.

The following example incorrectly relies on the return value of PDO->exec(), wherein a statement that affected 0 rows results in a call to die():
<?php
$db->exec() or die($db->errorInfo());
?>

Esempi

Esempio 1. Issuing a DELETE statement

Count the number of rows deleted by a DELETE statement with no WHERE clause.

<?php
$dbh = new PDO('odbc:sample', 'db2inst1', 'ibmdb2');

/* Delete all rows from the FRUIT table */
$count = $dbh->exec("DELETE FROM fruit WHERE colour = 'red'");

/* Return number of rows that were deleted */
print("Deleted $count rows.\n");
?>

Il precedente esempio visualizzerà:

Deleted 1 rows.

Vedere anche:

PDO->prepare()
PDO->query()
PDOStatement->execute()



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PDO->errorInfo()RisaliPDO->getAttribute()