PHP PDOStatement:bindParam插入数据错误问题分析

复制代码 代码如下:

<?php
$dbh = new PDO('mysql:host=localhost;dbname=test', "test");

$query = <<<QUERY
  INSERT INTO `user` (`username`, `password`) VALUES (:username, :password);
QUERY;
$statement = $dbh->prepare($query);

$bind_params = array(':username' => "laruence", ':password' => "weibo");
foreach( $bind_params as $key => $value ){
    $statement->bindParam($key, $value);
}
$statement->execute();

复制代码 代码如下:

<?php
foreach( $bind_params as $key => $value ){
    $statement->bindParam($key, $value);
}

复制代码 代码如下:

<?php
//第一次循环
$value = $bind_params[":username"];
$statement->bindParam(":username", &$value); //此时, :username是对$value变量的引用

//第二次循环
$value = $bind_params[":password"]; //oops! $value被覆盖成了:password的值
$statement->bindParam(":password", &$value);

复制代码 代码如下:

<?php
$statement->bindParam(":username", $bind_params[":username"]); //$value是引用变量了
$statement->bindParam(":password", $bind_params[":password"]);

复制代码 代码如下:

<?php
foreach( $bind_params as $key => &$value ) { //注意这里
    $statement->bindParam($key, $value);
}