PDO::errorInfo	PDO::getAttribute

	Last updated: Mon, 16 Jul 2012

PDO::exec

(no version information, might be only in CVS)

PDO::exec -- Execute an SQL statement and return the number of affected rows

说明

int PDO::exec ( string statement )

警告

本函数是实验性的。本函数的行为，包括函数名称以及其它任何关于本函数的文档可能会在没有通知的情况下随 PHP 以后的发布而改变。使用本函数风险自担。

PDO::exec() prepares and 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 SELECT 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.

警告

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()); ?>

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("Return number of rows that were deleted:\n"); print("Deleted $count rows.\n"); ?>
上例将输出：
Return number of rows that were deleted: Deleted 1 rows.

参见

PDO::prepare()

PDO::query()

PDOStatement::execute()

PDO::errorInfo	PDO::getAttribute

	Last updated: Mon, 16 Jul 2012


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