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PDO::exec
(PHP 5 >= 5.1.0, PECL pdo >= 0.1.0)
PDO::exec — Execute an SQL statement and return the number of affected rows
Beschreibung
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().
Parameter-Liste
- statement
-
The SQL statement to prepare and execute.
Data inside the query should be properly escaped.
Rückgabewerte
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.
Diese Funktion kann sowohl das boolsche FALSE zurückliefern, als auch einen nicht-boolschen Wert, wie zum Beispiel 0 oder "", der von einem einfachen if-Statement als FALSE ausgewertet wird. Weitere Informationen entnehmen Sie bitte dem Abschnitt über die boolschen Typen. Benutzen Sie deshalb den === Operator, um den Rückgabewert dieser Funktion zu überprüfen.
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():
$db->exec() or die(print_r($db->errorInfo(), true));
Beispiele
Beispiel #1 Issuing a DELETE statement
Count the number of rows deleted by a DELETE statement with no WHERE clause.
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$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");
Das oben gezeigte Beispiel erzeugt folgende Ausgabe:
Deleted 1 rows.
Siehe auch
- PDO::prepare() - Prepares a statement for execution and returns a statement object
- PDO::query() - Executes an SQL statement, returning a result set as a PDOStatement object
- PDOStatement::execute() - Executes a prepared statement