PDO::exec

说明

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().

参数

返回值

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.

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()); ?>

范例

例子 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"); ?> 上例将输出： Deleted 1 rows.

参见