我使用PDO连接到数据库,但我不知道哪种方法比UPDATE,DELETE和INSERT,PDO :: exec或PDO :: excute的方法更好. 我应该使用哪个?
I use PDO to connect to my database and I don't know which method is better than the other one for UPDATE, DELETE and INSERT, PDO::exec or PDO::excute. Which should I use?
推荐答案尽管这两种方法都有类似的命名(exec,execute),但它们都打算在不同的场景中使用:
Although both methods have a similar naming (exec,execute) they're meant to be used in different scenarios:
exec用于获取受影响的行数.
exec is used to get the number of affected rows. /** * (PHP 5 >= 5.1.0, PECL pdo >= 0.1.0)<br/> * Execute an SQL statement and return the number of affected rows * @link php/manual/en/pdo.exec.php * @param string $statement <p> * The SQL statement to prepare and execute. * </p> * <p> * Data inside the query should be properly escaped. * </p> * @return int <b>PDO::exec</b> returns the number of rows that were modified * or deleted by the SQL statement you issued. If no rows were affected, * <b>PDO::exec</b> returns 0. * </p> * This function may * return Boolean <b>FALSE</b>, but may also return a non-Boolean value which * evaluates to <b>FALSE</b>. Please read the section on Booleans for more * information. Use the === * operator for testing the return value of this * function. * <p> * The following example incorrectly relies on the return value of * <b>PDO::exec</b>, wherein a statement that affected 0 rows * results in a call to <b>die</b>: * <code> * $db->exec() or die(print_r($db->errorInfo(), true)); * </code> */ public function exec ($statement) {}
示例:
$myQuery = "UPDATE users SET email = 'testing'"; $affectedRows = $db->exec($myQuery);
execute.
execute is used when you want to pass an array of parameters to be bind in the query.
/** * (PHP 5 >= 5.1.0, PECL pdo >= 0.1.0)<br/> * Executes a prepared statement * @link php/manual/en/pdostatement.execute.php * @param array $input_parameters [optional] <p> * An array of values with as many elements as there are bound * parameters in the SQL statement being executed. * All values are treated as <b>PDO::PARAM_STR</b>. * </p> * <p> * You cannot bind multiple values to a single parameter; for example, * you cannot bind two values to a single named parameter in an IN() * clause. * </p> * <p> * You cannot bind more values than specified; if more keys exist in * <i>input_parameters</i> than in the SQL specified * in the <b>PDO::prepare</b>, then the statement will * fail and an error is emitted. * </p> * @return bool <b>TRUE</b> on success or <b>FALSE</b> on failure. */ public function execute (array $input_parameters = null) {}示例(当然,这也可能是UPDATE或DELETE查询):
Example (of course this might be an UPDATE or DELETE query as well):
$myQuery = 'SELECT * FROM users WHERE username = :username'; $params = array(':username' => 'admin'); $db->query($myQuery)->execute($params);
query返回PDOStatement对象
query returns a PDOStatement object
/** * (PHP 5 >= 5.1.0, PECL pdo >= 0.2.0)<br/> * Executes an SQL statement, returning a result set as a PDOStatement object * @link php/manual/en/pdo.query.php * @param string $statement <p> * The SQL statement to prepare and execute. * </p> * <p> * Data inside the query should be properly escaped. * </p> * @return PDOStatement <b>PDO::query</b> returns a PDOStatement object, or <b>FALSE</b> * on failure. */ public function query ($statement) {}
有关更多信息,您可以访问 PHP文档,或者再次使用PHPStorm,您可以查看PDO.php类的源代码.
For more information you can visit the PHP Docs or in case you're using PHPStorm you can go though the source code of the PDO.php class.
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