How To Create A Simple REST API in PHP? Step By Step Guide!

https://www.codeofaninja.com/2017/02/create-simple-rest-api-in-php.html This post covers the following topics: 1.0 Project Overview 1.1 What is REST API? 1.2 Why do we need REST API? 1.3 Where REST API is used? 1.4 REST API in our tutorials 2.0 File structure 3.0 Setup the database 3.1 Create categories table 3.2 Dump data for categories table 3.3 Products table 3.4 Dump data for products table 3.5 Connect to database 4.0 Read products 4.1 Product object 4.2 Create file to read products 4.3 Connect to database and products table 4.4 Read products from the database 4.5 Add Product "read()" method 4.6 Tell the user no products found 4.7 Output 5.0 Create Product 5.1 Create create.php file 5.2 Product create() method 5.3 Output 6.0 Read One Product 6.1 Create read_one.php file 6.2 Product readOne() method 6.3 Output 7.0 Update product 7.1 Create “update.php” file 7.2 Product update() method 7.3 Output 8.0 Delete Product 8.1 Create “delete.php” file 8.2 Product delete() method 8.3 Output 9.0 Search Products 9.1 Create "search.php" file 9.2 Create "search()" method 9.3 Output 10.0 Paginate Products 10.1 Create "read_paging.php" file 10.2 Create "core.php" file 10.3 Create "readPaging()" method 10.4 Create "count()" method 10.5 Get "paging" array 10.6 Output 11.0 Read Categories 11.1 Category object 11.2 Create "read.php" file 11.3 Category "read()" method 11.4 Output 12.0 Download Source Codes 13.0 What's Next? 14.0 Related Tutorials 15.0 Notes Before we start, we want to let you know that your feedback is important to us! If you have a positive feedback about our work, please let us know. If there's a section in this tutorial that is confusing or hard to understand, we consider it as a problem. Please let us know as well. Write your positive feedback or detailed description of the problem in the comments section below. Before you write a comment, please read this guide and our code of conduct. Thank you! 1.0 PROJECT OVERVIEW 1.1 What is REST API? To define "REST API", we have to know what is "REST" and what is "API" first. I'll do my best to explain it in simple terms because REST has a lot of concepts inside of it that could mean a lot of things. REST stands for "REpresentational State Transfer". It is a concept or architecture for managing information over the internet. REST concepts are referred to as resources. A representation of a resource must be stateless. It is usually represented by JSON. This post is worth reading: How I Explained REST to My Wife? API stands for "Application Programming Interface". It is a set of rules that allows one piece of software application to talk to another. Those "rules" can include create, read, update and delete operations. If you want to learn more, watch the video below and read the musiccritic's YouTube camera review if you interested on making some videos. REST API enable your application to cooperate with one or several different applications using REST concepts. If you want to learn more, watch the video below. 1.2 Why do we need REST API? In many applications, REST API is a need because this is the lightest way to create, read, update or delete information between different applications over the internet or HTTP protocol. This information is presented to the user in an instant especially if you use JavaScript to render the data on a webpage. 1.3 Where REST API is used? REST API can be used by any application that can connect to the internet. If data from an application can be created, read, updated or deleted using another application, it usually means a REST API is used. 1.4 REST API in our tutorials A REST API is needed for our AJAX CRUD Tutorial. But don't mind it for now. We will do it one step at a time. You don't need to learn all of it as well. Just choose what you need to learn. Also, please note that this PHP REST API is not yet in its final form. We still have some work to do with .htaccess for better URLs and more. But one thing is for sure, this source codes is good enough and works for our JavaScript tutorials. 2.0 FILE STRUCTURE At the end of this tutorial, we will have the following folders and files. ├─ api/ ├─── config/ ├────── core.php - file used for core configuration ├────── database.php - file used for connecting to the database. ├─── objects/ ├────── product.php - contains properties and methods for "product" database queries. ├────── category.php - contains properties and methods for "category" database queries. ├─── product/ ├────── create.php - file that will accept posted product data to be saved to database. ├────── delete.php - file that will accept a product ID to delete a database record. ├────── read.php - file that will output JSON data based from "products" database records. ├────── read_paging.php - file that will output "products" JSON data with pagination. ├────── read_one.php - file that will accept product ID to read a record from the database. ├────── update.php - file that will accept a product ID to update a database record. ├────── search.php - file that will accept keywords parameter to search "products" database. ├─── category/ ├────── read.php - file that will output JSON data based from "categories" database records. ├─── shared/ ├────── utilities.php - file that will return pagination array. 3.0 SETUP THE DATABASE Using PhpMyAdmin, create a new api_db database. Yes, api_db is the database name. After that, run the following SQL queries to create new tables with sample data. 3.1 Create categories table CREATE TABLE IF NOT EXISTS `categories` ( `id` int(11) NOT NULL AUTO_INCREMENT, `name` varchar(256) NOT NULL, `description` text NOT NULL, `created` datetime NOT NULL, `modified` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=19 ; 3.2 Dump data for categories table INSERT INTO `categories` (`id`, `name`, `description`, `created`, `modified`) VALUES (1, 'Fashion', 'Category for anything related to fashion.', '2014-06-01 00:35:07', '2014-05-30 17:34:33'), (2, 'Electronics', 'Gadgets, drones and more.', '2014-06-01 00:35:07', '2014-05-30 17:34:33'), (3, 'Motors', 'Motor sports and more', '2014-06-01 00:35:07', '2014-05-30 17:34:54'), (5, 'Movies', 'Movie products.', '0000-00-00 00:00:00', '2016-01-08 13:27:26'), (6, 'Books', 'Kindle books, audio books and more.', '0000-00-00 00:00:00', '2016-01-08 13:27:47'), (13, 'Sports', 'Drop into new winter gear.', '2016-01-09 02:24:24', '2016-01-09 01:24:24'); 3.3 Products table CREATE TABLE IF NOT EXISTS `products` ( `id` int(11) NOT NULL AUTO_INCREMENT, `name` varchar(32) NOT NULL, `description` text NOT NULL, `price` decimal(10,0) NOT NULL, `category_id` int(11) NOT NULL, `created` datetime NOT NULL, `modified` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=65 ; 3.4 Dump data for products table INSERT INTO `products` (`id`, `name`, `description`, `price`, `category_id`, `created`, `modified`) VALUES (1, 'LG P880 4X HD', 'My first awesome phone!', '336', 3, '2014-06-01 01:12:26', '2014-05-31 17:12:26'), (2, 'Google Nexus 4', 'The most awesome phone of 2013!', '299', 2, '2014-06-01 01:12:26', '2014-05-31 17:12:26'), (3, 'Samsung Galaxy S4', 'How about no?', '600', 3, '2014-06-01 01:12:26', '2014-05-31 17:12:26'), (6, 'Bench Shirt', 'The best shirt!', '29', 1, '2014-06-01 01:12:26', '2014-05-31 02:12:21'), (7, 'Lenovo Laptop', 'My business partner.', '399', 2, '2014-06-01 01:13:45', '2014-05-31 02:13:39'), (8, 'Samsung Galaxy Tab 10.1', 'Good tablet.', '259', 2, '2014-06-01 01:14:13', '2014-05-31 02:14:08'), (9, 'Spalding Watch', 'My sports watch.', '199', 1, '2014-06-01 01:18:36', '2014-05-31 02:18:31'), (10, 'Sony Smart Watch', 'The coolest smart watch!', '300', 2, '2014-06-06 17:10:01', '2014-06-05 18:09:51'), (11, 'Huawei Y300', 'For testing purposes.', '100', 2, '2014-06-06 17:11:04', '2014-06-05 18:10:54'), (12, 'Abercrombie Lake Arnold Shirt', 'Perfect as gift!', '60', 1, '2014-06-06 17:12:21', '2014-06-05 18:12:11'), (13, 'Abercrombie Allen Brook Shirt', 'Cool red shirt!', '70', 1, '2014-06-06 17:12:59', '2014-06-05 18:12:49'), (26, 'Another product', 'Awesome product!', '555', 2, '2014-11-22 19:07:34', '2014-11-21 20:07:34'), (28, 'Wallet', 'You can absolutely use this one!', '799', 6, '2014-12-04 21:12:03', '2014-12-03 22:12:03'), (31, 'Amanda Waller Shirt', 'New awesome shirt!', '333', 1, '2014-12-13 00:52:54', '2014-12-12 01:52:54'), (42, 'Nike Shoes for Men', 'Nike Shoes', '12999', 3, '2015-12-12 06:47:08', '2015-12-12 05:47:08'), (48, 'Bristol Shoes', 'Awesome shoes.', '999', 5, '2016-01-08 06:36:37', '2016-01-08 05:36:37'), (60, 'Rolex Watch', 'Luxury watch.', '25000', 1, '2016-01-11 15:46:02', '2016-01-11 14:46:02'); 3.5 Connect to database The code below shows the database credentials and a method to get a database connection using PDO. If you're not yet familiar with PDO, please learn from our PHP OOP CRUD Tutorial first. Create api folder. Open api folder. Create config folder. Open config folder. Create database.php file. Place the following code inside it. conn = null; try{ $this->conn = new PDO("mysql:host=" . $this->host . ";dbname=" . $this->db_name, $this->username, $this->password); $this->conn->exec("set names utf8"); }catch(PDOException $exception){ echo "Connection error: " . $exception->getMessage(); } return $this->conn; } } ?> 4.0 READ PRODUCTS 4.1 Product object The code below shows a class named Product with several of its properties. It also shows a constructor method that will accept the database connection. We will use this class to read data from the database. Open api folder. Create objects folder. Open objects folder. Create product.php file. Place the following code inside it. conn = $db; } } 4.2 Create file to read products The code below shows headers about who can read this file and which type of content it will return. In this case, our read.php file can be read by anyone (asterisk * means all) and will return a data in JSON format. Open api folder. Create product folder. Open product folder. Create read.php file. Place the following code inside it. getConnection(); // initialize object $product = new Product($db); // read products will be here 4.4 Read products from the database In the code below, we used the read() method of Product class to read data from the database. Through the $num variable, we check if there are records found. If there are records found, we loop through it using the while loop, add each record to the $products_arr array, set a 200 OK response code and show it to the user in JSON format. Replace of // read products will be here comment of read.php file with the following code. // query products $stmt = $product->read(); $num = $stmt->rowCount(); // check if more than 0 record found if($num>0){ // products array $products_arr=array(); $products_arr["records"]=array(); // retrieve our table contents // fetch() is faster than fetchAll() // http://stackoverflow.com/questions/2770630/pdofetchall-vs-pdofetch-in-a-loop while ($row = $stmt->fetch(PDO::FETCH_ASSOC)){ // extract row // this will make $row['name'] to // just $name only extract($row); $product_item=array( "id" => $id, "name" => $name, "description" => html_entity_decode($description), "price" => $price, "category_id" => $category_id, "category_name" => $category_name ); array_push($products_arr["records"], $product_item); } // set response code - 200 OK http_response_code(200); // show products data in json format echo json_encode($products_arr); } // no products found will be here 4.5 Add product "read()" method We used the read() method on the previous section but it does not exist yet in the Product class. We need to add this read() method. The code below shows the query to get records from the database. Open objects folder. Open product.php file. Place the following code inside the Product class. To make sure you added it correctly, put the code before the last closing curly brace. // read products function read(){ // select all query $query = "SELECT c.name as category_name, p.id, p.name, p.description, p.price, p.category_id, p.created FROM " . $this->table_name . " p LEFT JOIN categories c ON p.category_id = c.id ORDER BY p.created DESC"; // prepare query statement $stmt = $this->conn->prepare($query); // execute query $stmt->execute(); return $stmt; } 4.6 Tell the user no products found If the $num variable has a value of zero or negative, it means there are no records returned from the database. We need to tell the user about this. On the code below, we set the response code to 404 - Not found and a message that says No products found. Replace of // no products found will be here comment of read.php file with the following code. else{ // set response code - 404 Not found http_response_code(404); // tell the user no products found echo json_encode( array("message" => "No products found.") ); } 4.7 Output You need to use POSTMAN to test our API. Download your version of POSTMAN here. Launch POSTMAN. Enter the following as the request URL. http://localhost/api/product/read.php Click the blue "Send" button. Output if there are product data. Output if there are no product data. 5.0 CREATE PRODUCT 5.1 Create create.php file Open product folder. Create a new create.php file. Open that file and put the following code inside it. getConnection(); $product = new Product($db); // get posted data $data = json_decode(file_get_contents("php://input")); // make sure data is not empty if( !empty($data->name) && !empty($data->price) && !empty($data->description) && !empty($data->category_id) ){ // set product property values $product->name = $data->name; $product->price = $data->price; $product->description = $data->description; $product->category_id = $data->category_id; $product->created = date('Y-m-d H:i:s'); // create the product if($product->create()){ // set response code - 201 created http_response_code(201); // tell the user echo json_encode(array("message" => "Product was created.")); } // if unable to create the product, tell the user else{ // set response code - 503 service unavailable http_response_code(503); // tell the user echo json_encode(array("message" => "Unable to create product.")); } } // tell the user data is incomplete else{ // set response code - 400 bad request http_response_code(400); // tell the user echo json_encode(array("message" => "Unable to create product. Data is incomplete.")); } ?> 5.2 Product create() method Open objects folder. Open product.php file. The previous section will not work without the following code inside the Product (objects/product.php) class. // create product function create(){ // query to insert record $query = "INSERT INTO " . $this->table_name . " SET name=:name, price=:price, description=:description, category_id=:category_id, created=:created"; // prepare query $stmt = $this->conn->prepare($query); // sanitize $this->name=htmlspecialchars(strip_tags($this->name)); $this->price=htmlspecialchars(strip_tags($this->price)); $this->description=htmlspecialchars(strip_tags($this->description)); $this->category_id=htmlspecialchars(strip_tags($this->category_id)); $this->created=htmlspecialchars(strip_tags($this->created)); // bind values $stmt->bindParam(":name", $this->name); $stmt->bindParam(":price", $this->price); $stmt->bindParam(":description", $this->description); $stmt->bindParam(":category_id", $this->category_id); $stmt->bindParam(":created", $this->created); // execute query if($stmt->execute()){ return true; } return false; } 5.3 Output To test for successful creation of a product, open POSTMAN. Enter the following as the request URL http://localhost/api/product/create.php Click "Body" tab. Click "raw". Enter this JSON value: { "name" : "Amazing Pillow 2.0", "price" : "199", "description" : "The best pillow for amazing programmers.", "category_id" : 2, "created" : "2018-06-01 00:35:07" } It should look like this: If the system is unable to create the product, it should look like this: If the sent data is incomplete, for example, it is missing the price data, output should look like this: 6.0 READ ONE PRODUCT 6.1 Create read_one.php file Open product folder. Create new read_one.php file. Open that file and put the following code. getConnection(); // prepare product object $product = new Product($db); // set ID property of record to read $product->id = isset($_GET['id']) ? $_GET['id'] : die(); // read the details of product to be edited $product->readOne(); if($product->name!=null){ // create array $product_arr = array( "id" => $product->id, "name" => $product->name, "description" => $product->description, "price" => $product->price, "category_id" => $product->category_id, "category_name" => $product->category_name ); // set response code - 200 OK http_response_code(200); // make it json format echo json_encode($product_arr); } else{ // set response code - 404 Not found http_response_code(404); // tell the user product does not exist echo json_encode(array("message" => "Product does not exist.")); } ?> 6.2 Product readOne() method Open objects folder. Open product.php file. The previous section will not work without the following code inside the Product class. // used when filling up the update product form function readOne(){ // query to read single record $query = "SELECT c.name as category_name, p.id, p.name, p.description, p.price, p.category_id, p.created FROM " . $this->table_name . " p LEFT JOIN categories c ON p.category_id = c.id WHERE p.id = ? LIMIT 0,1"; // prepare query statement $stmt = $this->conn->prepare( $query ); // bind id of product to be updated $stmt->bindParam(1, $this->id); // execute query $stmt->execute(); // get retrieved row $row = $stmt->fetch(PDO::FETCH_ASSOC); // set values to object properties $this->name = $row['name']; $this->price = $row['price']; $this->description = $row['description']; $this->category_id = $row['category_id']; $this->category_name = $row['category_name']; } 6.3 Output First, we will test for a product that exists. Open POSTMAN. Enter the following as the request URL. Click the blue "Send" button. http://localhost/api/product/read_one.php?id=60 Next, we will test for a product that does not exist. Enter the following as the request URL. Click the blue "Send" button. http://localhost/api/product/read_one.php?id=999 7.0 UPDATE PRODUCT 7.1 Create "update.php" file Open product folder. Create new update.php file. Open that file and put the following code inside it. getConnection(); // prepare product object $product = new Product($db); // get id of product to be edited $data = json_decode(file_get_contents("php://input")); // set ID property of product to be edited $product->id = $data->id; // set product property values $product->name = $data->name; $product->price = $data->price; $product->description = $data->description; $product->category_id = $data->category_id; // update the product if($product->update()){ // set response code - 200 ok http_response_code(200); // tell the user echo json_encode(array("message" => "Product was updated.")); } // if unable to update the product, tell the user else{ // set response code - 503 service unavailable http_response_code(503); // tell the user echo json_encode(array("message" => "Unable to update product.")); } ?> 7.2 Product update() method Open objects folder. Open product.php file. The previous section will not work without the following code inside the Product class. // update the product function update(){ // update query $query = "UPDATE " . $this->table_name . " SET name = :name, price = :price, description = :description, category_id = :category_id WHERE id = :id"; // prepare query statement $stmt = $this->conn->prepare($query); // sanitize $this->name=htmlspecialchars(strip_tags($this->name)); $this->price=htmlspecialchars(strip_tags($this->price)); $this->description=htmlspecialchars(strip_tags($this->description)); $this->category_id=htmlspecialchars(strip_tags($this->category_id)); $this->id=htmlspecialchars(strip_tags($this->id)); // bind new values $stmt->bindParam(':name', $this->name); $stmt->bindParam(':price', $this->price); $stmt->bindParam(':description', $this->description); $stmt->bindParam(':category_id', $this->category_id); $stmt->bindParam(':id', $this->id); // execute the query if($stmt->execute()){ return true; } return false; } 7.3 Output Open POSTMAN. Enter the following as the request URL. http://localhost/api/product/update.php Click "Body" tab. Click "raw". Enter the following JSON value (make sure the ID exists in your database) and click the blue "Send" button. { "id" : "106", "name" : "Amazing Pillow 3.0", "price" : "255", "description" : "The best pillow for amazing programmers.", "category_id" : 2, "created" : "2018-08-01 00:35:07" } The product ID 106, is just an example. You need to specify a product ID that exists in your database. If you specify an ID that does not exist in the database, it might still say "product was updated. It does not update anything on the database but the query was executed successfully without any syntax errors. To prevent this, you need an extra validation where you check if an ID exists in the database. This feature is not yet part of our tutorial. If updating a product is successful, it should look like this: If the system fails to update the product, output will look like this: 8.0 DELETE PRODUCT 8.1 Create "delete.php" file Open product folder. Create new delete.php file. Open that file and put the following code inside it. getConnection(); // prepare product object $product = new Product($db); // get product id $data = json_decode(file_get_contents("php://input")); // set product id to be deleted $product->id = $data->id; // delete the product if($product->delete()){ // set response code - 200 ok http_response_code(200); // tell the user echo json_encode(array("message" => "Product was deleted.")); } // if unable to delete the product else{ // set response code - 503 service unavailable http_response_code(503); // tell the user echo json_encode(array("message" => "Unable to delete product.")); } ?> 8.2 Product delete() method Open objects folder. Open product.php file. The previous section will not work without the following code inside the Product class. // delete the product function delete(){ // delete query $query = "DELETE FROM " . $this->table_name . " WHERE id = ?"; // prepare query $stmt = $this->conn->prepare($query); // sanitize $this->id=htmlspecialchars(strip_tags($this->id)); // bind id of record to delete $stmt->bindParam(1, $this->id); // execute query if($stmt->execute()){ return true; } return false; } 8.3 Output Open POSTMAN. Enter the following as the request URL. http://localhost/api/product/delete.php Click "Body" tab. Click "raw". Enter the following JSON value (make sure the ID exists in your database) and click the blue "Send" button. { "id" : "106" } If a product was successfully deleted, it should look like this: If the system fails to delete the product, output will look like this: 9.0 SEARCH PRODUCTS 9.1 Create "search.php" file Open product folder. Create search.php file. Open that file and place the following code. getConnection(); // initialize object $product = new Product($db); // get keywords $keywords=isset($_GET["s"]) ? $_GET["s"] : ""; // query products $stmt = $product->search($keywords); $num = $stmt->rowCount(); // check if more than 0 record found if($num>0){ // products array $products_arr=array(); $products_arr["records"]=array(); // retrieve our table contents // fetch() is faster than fetchAll() // http://stackoverflow.com/questions/2770630/pdofetchall-vs-pdofetch-in-a-loop while ($row = $stmt->fetch(PDO::FETCH_ASSOC)){ // extract row // this will make $row['name'] to // just $name only extract($row); $product_item=array( "id" => $id, "name" => $name, "description" => html_entity_decode($description), "price" => $price, "category_id" => $category_id, "category_name" => $category_name ); array_push($products_arr["records"], $product_item); } // set response code - 200 OK http_response_code(200); // show products data echo json_encode($products_arr); } else{ // set response code - 404 Not found http_response_code(404); // tell the user no products found echo json_encode( array("message" => "No products found.") ); } ?> 9.2 Create search() method Open objects folder. Open product.php file. Add the following search() method. // search products function search($keywords){ // select all query $query = "SELECT c.name as category_name, p.id, p.name, p.description, p.price, p.category_id, p.created FROM " . $this->table_name . " p LEFT JOIN categories c ON p.category_id = c.id WHERE p.name LIKE ? OR p.description LIKE ? OR c.name LIKE ? ORDER BY p.created DESC"; // prepare query statement $stmt = $this->conn->prepare($query); // sanitize $keywords=htmlspecialchars(strip_tags($keywords)); $keywords = "%{$keywords}%"; // bind $stmt->bindParam(1, $keywords); $stmt->bindParam(2, $keywords); $stmt->bindParam(3, $keywords); // execute query $stmt->execute(); return $stmt; } 9.3 Output Open POSTMAN. Enter the following as the request URL. http://localhost/api/product/search.php?s=shirt Click the blue "Send" button. If there was a product found, it should look like this: If there are no products found, output will look like this: 10.0 PAGINATE PRODUCTS 10.1 Create "read_paging.php" file Open product folder. Create read_paging.php file. getConnection(); // initialize object $product = new Product($db); // query products $stmt = $product->readPaging($from_record_num, $records_per_page); $num = $stmt->rowCount(); // check if more than 0 record found if($num>0){ // products array $products_arr=array(); $products_arr["records"]=array(); $products_arr["paging"]=array(); // retrieve our table contents // fetch() is faster than fetchAll() // http://stackoverflow.com/questions/2770630/pdofetchall-vs-pdofetch-in-a-loop while ($row = $stmt->fetch(PDO::FETCH_ASSOC)){ // extract row // this will make $row['name'] to // just $name only extract($row); $product_item=array( "id" => $id, "name" => $name, "description" => html_entity_decode($description), "price" => $price, "category_id" => $category_id, "category_name" => $category_name ); array_push($products_arr["records"], $product_item); } // include paging $total_rows=$product->count(); $page_url="{$home_url}product/read_paging.php?"; $paging=$utilities->getPaging($page, $total_rows, $records_per_page, $page_url); $products_arr["paging"]=$paging; // set response code - 200 OK http_response_code(200); // make it json format echo json_encode($products_arr); } else{ // set response code - 404 Not found http_response_code(404); // tell the user products does not exist echo json_encode( array("message" => "No products found.") ); } ?> 10.2 Create "core.php" file This file holds our core configuration like the home URL and pagination variables. Open the config folder and create core.php file. Open core.php file and place the following code. 10.3 Create "readPaging()" method Open objects folder. Open product.php file. Add the following method inside product class. This method will return a list of records limited to what we set in $records_per_page of the previous section. // read products with pagination public function readPaging($from_record_num, $records_per_page){ // select query $query = "SELECT c.name as category_name, p.id, p.name, p.description, p.price, p.category_id, p.created FROM " . $this->table_name . " p LEFT JOIN categories c ON p.category_id = c.id ORDER BY p.created DESC LIMIT ?, ?"; // prepare query statement $stmt = $this->conn->prepare( $query ); // bind variable values $stmt->bindParam(1, $from_record_num, PDO::PARAM_INT); $stmt->bindParam(2, $records_per_page, PDO::PARAM_INT); // execute query $stmt->execute(); // return values from database return $stmt; } 10.4 Create "count()" method Still in the product class (product.php file), add the following method. The total rows are needed to build the pagination array. It is included in the 'paging' computation. // used for paging products public function count(){ $query = "SELECT COUNT(*) as total_rows FROM " . $this->table_name . ""; $stmt = $this->conn->prepare( $query ); $stmt->execute(); $row = $stmt->fetch(PDO::FETCH_ASSOC); return $row['total_rows']; } 10.5 Get "paging" array Create shared folder. Open shared folder. Create utilities.php file. Open utilities.php file and place the following code. 1 ? "{$page_url}page=1" : ""; // count all products in the database to calculate total pages $total_pages = ceil($total_rows / $records_per_page); // range of links to show $range = 2; // display links to 'range of pages' around 'current page' $initial_num = $page - $range; $condition_limit_num = ($page + $range) + 1; $paging_arr['pages']=array(); $page_count=0; for($x=$initial_num; $x<$condition_limit_num; $x++){ // be sure '$x is greater than 0' AND 'less than or equal to the $total_pages' if(($x > 0) && ($x <= $total_pages)){ $paging_arr['pages'][$page_count]["page"]=$x; $paging_arr['pages'][$page_count]["url"]="{$page_url}page={$x}"; $paging_arr['pages'][$page_count]["current_page"] = $x==$page ? "yes" : "no"; $page_count++; } } // button for last page $paging_arr["last"] = $page<$total_pages ? "{$page_url}page={$total_pages}" : ""; // json format return $paging_arr; } } ?> 10.6 Output Open POSTMAN. Enter the following as the request URL. http://localhost/api/product/read_paging.php Click the blue "Send" button. If there are products found, scroll down to see the paging node. It should look like this: If there are no products found, output will look like this: 11.0 READ CATEGORIES 11.1 Create "category.php" file Open objects folder. Create new category.php file. Place the following code inside the category.php file. conn = $db; } // used by select drop-down list public function readAll(){ //select all data $query = "SELECT id, name, description FROM " . $this->table_name . " ORDER BY name"; $stmt = $this->conn->prepare( $query ); $stmt->execute(); return $stmt; } } ?> 11.2 Create "read.php" file Create new category folder. Open that folder and create new read.php file inside it. Open read.php file and place the following code. getConnection(); // initialize object $category = new Category($db); // query categorys $stmt = $category->read(); $num = $stmt->rowCount(); // check if more than 0 record found if($num>0){ // products array $categories_arr=array(); $categories_arr["records"]=array(); // retrieve our table contents // fetch() is faster than fetchAll() // http://stackoverflow.com/questions/2770630/pdofetchall-vs-pdofetch-in-a-loop while ($row = $stmt->fetch(PDO::FETCH_ASSOC)){ // extract row // this will make $row['name'] to // just $name only extract($row); $category_item=array( "id" => $id, "name" => $name, "description" => html_entity_decode($description) ); array_push($categories_arr["records"], $category_item); } // set response code - 200 OK http_response_code(200); // show categories data in json format echo json_encode($categories_arr); } else{ // set response code - 404 Not found http_response_code(404); // tell the user no categories found echo json_encode( array("message" => "No categories found.") ); } ?> 11.3 Add Category "read()" method Open objects folder. Open category.php file. The previous section's code will not work without the following code inside the category.php file. Add the following method inside the Category class. // used by select drop-down list public function read(){ //select all data $query = "SELECT id, name, description FROM " . $this->table_name . " ORDER BY name"; $stmt = $this->conn->prepare( $query ); $stmt->execute(); return $stmt; } 11.4 Output Open POSTMAN. Enter the following as the request URL. http://localhost/api/category/read.php Click the blue "Send" button. If there are categories found, it should look like this: If there are no categories found, output will look like this: 12.0 DOWNL