{"id":2156,"date":"2021-07-08T03:46:23","date_gmt":"2021-07-08T03:46:23","guid":{"rendered":"https:\/\/phptutorial.net\/?page_id=2156"},"modified":"2021-07-08T03:49:38","modified_gmt":"2021-07-08T03:49:38","slug":"pdo-fetch_class","status":"publish","type":"page","link":"https:\/\/www.phptutorial.net\/php-pdo\/pdo-fetch_class\/","title":{"rendered":"PDO FETCH_CLASS"},"content":{"rendered":"\n

Summary<\/strong>: in this tutorial, you’ll learn how to use the PDO::FETCH_CLASS<\/code> mode to fetch data into an object of a class.<\/p>\n\n\n\n

Introduction to the PDO::FETCH_CLASS mode #<\/a><\/h2>\n\n\n\n

Suppose that you have the following books<\/code> table in the database:<\/p>\n\n\n

CREATE<\/span> TABLE<\/span> IF<\/span> NOT<\/span> EXISTS<\/span> books (\r\n    book_id INT<\/span> AUTO_INCREMENT,\r\n    title VARCHAR<\/span>(255<\/span>) NOT<\/span> NULL<\/span>,\r\n    isbn VARCHAR<\/span>(13<\/span>) NULL<\/span>,\r\n    published_date DATE<\/span> NULL<\/span>,\r\n    publisher_id INT<\/span> NULL<\/span>,\r\n    PRIMARY KEY<\/span> (book_id),\r\n    CONSTRAINT<\/span> fk_publisher FOREIGN<\/span> KEY<\/span> (publisher_id)\r\n        REFERENCES<\/span> publishers (publisher_id)\r\n);<\/code><\/span>Code language:<\/span> SQL (Structured Query Language)<\/span> (<\/span>sql<\/span>)<\/span><\/small><\/pre>\n\n\n
class<\/span> Book<\/span>\n<\/span>{\n}<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
Each row in the books<\/code> table can map to an instance of the Book<\/code> class.<\/p>\n\n\n\n
To select data from the books<\/code> table and map the columns to the properties of a Book<\/code> object, you can use the PDO::FETCH_CLASS<\/code> mode. For example:<\/p>\n\n\n
<?php<\/span>\n\nclass<\/span> Book<\/span>\n<\/span>{\n}\n\n$pdo = require<\/span> 'connect.php'<\/span>;\n\n$sql = 'SELECT book_id, title, isbn, published_date\n        FROM books\n        WHERE book_id = :book_id'<\/span>;\n\n$statement = $pdo->prepare($sql);\n$statement->execute([':book_id'<\/span> => 1<\/span>]);\n$statement->setFetchMode(PDO::FETCH_CLASS, 'Book'<\/span>);\n$book = $statement->fetch();\n\nvar_dump($book);<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
Output:<\/p>\n\n\n
object(Book)#3 (4) {\n    [\"book_id\"]=>  string(1) \"1\"\n    [\"title\"]=>  string(43) \"CISSP All-in-One Exam Guide, Eighth Edition\"\n    [\"isbn\"]=>  string(13) \"9781260142655\"\n    [\"published_date\"]=>  string(10) \"2018-09-28\"\n}<\/code><\/span>Code language:<\/span> plaintext<\/span> (<\/span>plaintext<\/span>)<\/span><\/small><\/pre>\n\n\n
How it works.<\/p>\n\n\n\n
First, define a class called Book<\/code>:<\/p>\n\n\n
class<\/span> Book<\/span>\n<\/span>{\n}<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
$pdo = require<\/span> 'connect.php'<\/span>;<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
Then, select a row with id 1 from the books<\/code> table:<\/p>\n\n\n
$sql = 'SELECT book_id, title, isbn, published_date\n        FROM books\n        WHERE book_id = :book_id'<\/span>;\n\n$statement = $pdo->prepare($sql);\n$statement->execute([':book_id'<\/span> => 1<\/span>]);<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
After that, set the fetch mode to PDO::FETCH_CLASS<\/code> and pass the Book<\/code> class name to the second argument of the setFetchMode()<\/code> method:<\/p>\n\n\n
$statement->setFetchMode(PDO::FETCH_CLASS, 'Book'<\/span>);<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
Finally, fetch the data from the books<\/code> table to the properties of the Book<\/code> class:<\/p>\n\n\n
$book = $statement->fetch();<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
Note that if the Book class doesn’t exist, PDO will return an array instead of an object.<\/p>\n\n\n\n
The PDO::FETCH_CLASS<\/code> uses the following rules when assigning column values to the object properties:<\/p>\n\n\n\n
Next, connect to the bookdb<\/code> database<\/a> using the connect.php<\/code> script:<\/p>\n\n\n
And the Book<\/code> class in PHP<\/a>:<\/p>\n\n\n