PDO full guide with examples and a complete crud code step by step 2022

Hi devs in this guide we are going to see PDO "PHP Data Objects". lets get started we are going to create a crud to see the deference and benefits of pdo.

So how PDO secures our queries, Here is a example

// Normal Query

// Unsafe approach

$id = 10;
$posts = $pdo->query("SELECT * FROM blog WHERE blog_id='$id'"); // Here we are passing id directly in sql query which can be insecure.


while($row = $posts->fetch())
{
    echo $row->title."<br/>";
}

So when doing a query to database why not prepare it first and pass parameters in query instead direct variable.

Let's see the "Insert query" using PDO.

 // Insert query.


        $post = $pdo->prepare("INSERT INTO blog(`title`, `description`) VALUES (:title, :details)");
        $post->execute([
            'title' => $title,
            'details' => $details,
        ]); 

We defined named parameters

:title  and :details both are parameters and we are setting values to these parameters 

here

$post->execute([
            'title' => $title,
            'details' => $details,
]); 

Similar way we deal with update query

  $post = $pdo->prepare("UPDATE blog SET `description` = :details WHERE title=:title");
        $post->execute([
            'title' => $title,
            'details' => $details,
        ]);

PDO also offer unnamed parameters, Note order you assign values to unnamed parameters matters.

Here we use unnamed parameters to delete record.

 $post = $pdo->prepare("DELETE from blog WHERE id=?");
 $post->execute([$_GET['id']]);

Here ? is unnamed parameter and gets value from $_GET['id']

Hope this helps, Check our video guide for better understanding and working examples.