Database Engine in PHP

Let's now make a website engine where the content of the pages will be stored not in files, but in a database. Suppose we have the following table in the database:

Suppose we want to get our pages by URLs like /page/1, where the number will represent the id of the page we want to get.

Let's start the implementation. First, in a separate file, we will make a connection to the database and connect this file to ours:

index.php<?php
  $link = require 'connect.php';
?>

Get the requested URL:

index.php<?php
  $url = $_SERVER['REQUEST_URI'];
?>

Using a regular expression, split the URL into parts:

index.php<?php
  preg_match('#/page/(\d+)#', $url, $match);
?>

Write the id from the capture group into a variable:

index.php<?php
  $id = $match[1];
?>

Execute a query to the database, getting the requested page by id:

index.php<?php
  $query = "SELECT * FROM pages WHERE id=$id";
  $res = mysqli_query($link, $query) or die(mysqli_error($link));
  $page = mysqli_fetch_assoc($res);
?>

Get the template file:

index.php<?php
  $layout = file_get_contents('layout.php');
?>

In the template file, perform the insertion of the title and content:

index.php<?php
  $layout = str_replace('{{ title }}', $page['title'], $layout);
  $layout = str_replace('{{ content }}', $page['content'], $layout);
?>

Send the assembled website page to the browser:

index.php<?php
  echo $layout;
?>

Let's put it all together and get the following code:

index.php<?php
  require 'connect.php';
  
  $url = $_SERVER['REQUEST_URI'];
  preg_match('#/page/(\d+)#', $url, $match);
  $id = $match[1];
  
  $query  = "SELECT * FROM pages WHERE id=$id";
  $res = mysqli_query($link, $query) or die(mysqli_error($link));
  $page   = mysqli_fetch_assoc($res);
  
  $layout = file_get_contents('layout.php');
  $layout = str_replace('{{ title }}', $page['title'], $layout);
  $layout = str_replace('{{ content }}', $page['content'], $layout);
  
  echo $layout;
?>