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php method to implement SQL injection prevention: 1. execute parameter method, the code is [$stmt->execute(array($_POST[$j], $_POST[$i])]; 2. bindParam binds parameters, the code is [$stmt->bindPara("")].
php implements sql anti-injection method:
Method 1: execute substitute parameters
<?php if(count($_POST)!= 0) { $host = 'aaa'; $database = 'bbb'; $username = 'ccc'; $password = '***'; $num = 0; $pdo = new PDO("mysql:host=$host;dbname=$database", $username, $password);//创建一个pdo对象 foreach ($_POST as $var_Key => $var_Value) { //获取POST数组最大值 $num = $num + 1; } //下标为i的数组存储的是商品id, 下标为j数组的存储的是此商品的库存 for($i=0;$i<$num;$i=$i+2) { //库存下标 $j = $i+1; //判断传递过来的数据合法性 if(is_numeric(trim($_POST[$i])) && is_numeric(trim($_POST[$j]))){ //禁用prepared statements的仿真效果 $pdo->setAttribute(PDO::ATTR_EMULATE_PREPARES, false); //查询数据库中是否存在该ID的商品 //当调用 prepare() 时,查询语句已经发送给了数据库服务器,此时只有占位符 ? 发送过去,没有用户提交的数据 $stmt = $pdo->prepare("select good_id from delphi_test_content WHERE good_id = ?"); //当调用到 execute()时,用户提交过来的值才会传送给数据库,他们是分开传送的,两者独立的,SQL攻击者没有一点机会。 $stmt->execute(array($_POST[$i])); //返回查询结果 $count = $stmt->rowCount(); //如果本地数据库存在该商品ID和库存记录,就更新该商品的库存 if($count != 0) { $stmt = $pdo->prepare("update delphi_test_content set content = ? WHERE good_id = ?"); $stmt->execute(array($_POST[$j], $_POST[$i])); } //如果本地数据库没有该商品ID和库存记录,就新增该条记录 if($count == 0) { $stmt = $pdo->prepare("insert into delphi_test_content (good_id,content) values (?,?)"); $stmt->execute(array($_POST[$i], $_POST[$j])); } } } $pdo = null; //关闭连接 } ?>
Method 2: bindParam binding parameters
<?php if(count($_POST)!= 0) { $host = 'aaa'; $database = 'bbb'; $username = 'ccc'; $password = '***'; $num = 0; $pdo = new PDO("mysql:host=$host;dbname=$database", $username, $password);//创建一个pdo对象 foreach ($_POST as $var_Key => $var_Value) { //获取POST数组最大值 $num = $num + 1; } //下标为i的数组存储的是商品id, 下标为j数组的存储的是此商品的库存 for($i=0;$i<$num;$i=$i+2) { //库存下标 $j = $i+1; //判断传递过来的数据合法性(此数据为商品编号以及库存,严格来说字符串全是由数字组成的) if(is_numeric(trim($_POST[$i])) && is_numeric(trim($_POST[$j]))){ //查询数据库中是否存在该ID的商品 $stmt = $pdo->prepare("select good_id from delphi_test_content WHERE good_id = ?"); $stmt->execute(array($_POST[$i])); $stmt->bindParam(1,$_POST[$i]); $stmt->execute(); //返回查询结果 $count = $stmt->rowCount(); //如果本地数据库存在该商品ID和库存记录,就更新该商品的库存 if($count != 0) { $stmt = $pdo->prepare("update delphi_test_content set content = ? WHERE good_id = ?"); $stmt->execute(array($_POST[$j], $_POST[$i])); $stmt->bindParam(1,$_POST[$j]); $stmt->bindParam(2,$_POST[$i]); $stmt->execute(); } //如果本地数据库没有该商品ID和库存记录,就新增该条记录 if($count == 0) { $stmt = $pdo->prepare("insert into delphi_test_content (good_id,content) values (?,?)"); $stmt->bindParam(1,$_POST[$i]); $stmt->bindParam(2,$_POST[$j]); $stmt->execute(); } } } $pdo = null; //关闭连接 } ?>
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