Insert and Select operation using PDO

PDO_Example.php

<?php
	$server_name = 'localhost';
	$db_username = 'DB_USERNAME';
	$db_password = 'DB_PASSWORD';
	$db_name = 'DB_NAME';
	
	try{
		$conn = new PDO("mysql:host=$server_name;dbname=$db_name",$db_username,$db_password);
		$conn -> setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
		
		$username = 'newuser2';
		$blog_text = 'blog text of newuser2';
		$sql_query = "INSERT INTO users(`username`,`blog_text`) VALUES ( :username, :blog_text )";
		$stmt = $conn -> prepare($sql_query);
		$stmt -> bindParam(':username',$username);
		$stmt -> bindParam(':blog_text',$blog_text);
		$stmt -> execute();
		
		
		$sql_query = "SELECT * FROM users";
		$stmt = $conn -> prepare($sql_query);
		$stmt -> execute();
		$res = $stmt -> fetchAll(PDO::FETCH_ASSOC);
		foreach($res as $row){
			echo $row['username'].'-->'.$row['blog_text']."<br>";
		}
		
	}
	catch(Exception $e){
		echo 'Exception: '.$e->getMessage().'<br>';
	}
?>