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PDO
PHP Manual

PDO->exec()

(PHP 5 >= 5.1.0, PECL pdo:0.1-1.0.3)

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

说明

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().

参数

statement

The SQL statement to prepare and execute.

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.

Warning

本函数可能返回布尔值 FALSE，但也可能返回一个与 FALSE 等值的非布尔值，例如 0 或者 ""。请参阅布尔类型章节以获取更多信息。应使用 === 运算符来测试本函数的返回值。

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

Example#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

PDO
PHP Manual