如何使用php在字符串中转义单引号(撇号)

Question

我有这样的SQL查询: -

$stmt = $pdo->prepare(
   "SELECT * FROM `products_keywords` WHERE `product_type` = '" . $product_type . "' ");

我不知道$ product_type变量中的值是多少.但是现在,我在$ product_type变量中得到Men's Shirt,这导致我的SQL查询中出现语法错误.我确定这个错误是由于Men's Shirt值的单引号引起的.我如何根据我的查询来逃避这个值？以及如何检查我的$ product_type变量中是否有单引号然后根据我的查询转义它.提前致谢.

Answer 1

答案是你不需要.使用PDO准备的正确方法是这样的:

$stmt = $pdo->prepare(
   "SELECT * FROM `products_keywords` WHERE `product_type` = ?");

这是使用预备声明的重点.然后绑定参数,如下所示:

$stmt->bindParam(1, $product_type)

证明,

架构:

create table `products_keywords`
(   `id` int not null,
    `products_keywords` varchar(1000) not null,
    `product_type` varchar(100) not null
);
insert `products_keywords` (`id`,`products_keywords`,`product_type`) values  
(1,'zoom lawn cut mower',"Lawn Mower"),
(2,'stylish torso Polo','Men\'s Shirt');

查看数据:

select * from `products_keywords`;
+----+---------------------+--------------+
| id | products_keywords   | product_type |
+----+---------------------+--------------+
|  1 | zoom lawn cut mower | Lawn Mower   |
|  2 | stylish torso Polo  | Men's Shirt  |
+----+---------------------+--------------+

PHP:

<?php
    // turn on error reporting, or wonder why nothing is happening at times
    error_reporting(E_ALL);
    ini_set("display_errors", 1);    

    $servername="localhost";
    $dbname="so_gibberish";
    $username="nate123";
    $password="openSesame1";

    try {
        $pdo = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);
        $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
        $pdo->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);

        $product_type="Men's Shirt";
        $stmt = $pdo->prepare("SELECT * FROM `products_keywords` WHERE `product_type` = ?");
        $stmt->bindParam(1, $product_type);
        $stmt->execute();
        while($row = $stmt->fetch()) {
            echo $row['id'].", ".$row['products_keywords'].", ".$row['product_type']."<br/>";
        }
    } catch (PDOException $e) {
        echo 'pdo problemo: ' . $e->getMessage();   // dev not production code
        exit();
    }
?>

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