Fetch all records from MySQL as lazy="false" with PHP

Question

I have 2 tables in my database users and users_roles, like so:

users:

id | username | user_role_id
----------------------------
 1 | User1    | 1
 2 | User2    | 1
 3 | User3    | 2

users_roles:

id | role 
----------
 1 | admin
 2 | user

So, in Java I just had to write in Hibernate mappings an attribute lazy="false" to just get a list of all users automatically containing users_roles objects too, each specifically for each record in users table, but in PHP? I just came across an option in the PDO called FETCH_ASSOC, but I cannot understand how it works.

My get all users list method looks like this:

public function getAll() {

    $conn = new PDO(DB_DSN, DB_USERNAME, DB_PASSWORD);

    $sql = $conn->prepare("SELECT * FROM users ORDER BY id DESC");

    $sql->execute();
    $list = $sql->fetchAll(PDO::FETCH_OBJ);

    $conn = null;

    return $list;
}

and the piece of code from the Smarty template:

{foreach from=$usersList item=item}                
    {$item->username}
    {$item->users_roles.role}
{/foreach}

Would you mind helping me a little to get on the right way to it?

Answer 1

FETCH_ASSOC option fetches the rows into an associative array like:

Array
(
    [0] => Array
        (
            [id] => 1
            [name] => name1
        )

    [1] => Array
        (
            [id] => 2
            [name] => name2
        )
)

If you want top get all the users, who have a corresponding record in users_roles table, you can use this request:

SELECT 
    *
FROM
    users
INNER JOIN
    users_roles
ON
    users_roles.id=users.user_role_id
ORDER BY
    users.id DESC

Answer 2

Unless you are using PHP frameworks such as CakePHP or Yii, you will have to create your own query to fetch related data.

SELECT * FROM users
LEFT JOIN users_roles ON users.user_role_id = users_roles.id

After that you can fetch the records and use them in your code.

Answer 3

The equivalent of PDO in Java is JDBC: you have statements and result sets, not business objects. Hibernate is an object-relational-mapping (ORM) library that allows mapping tables into business objects.

There are several ORMs for PHP, for example Doctrine and Propel. Search for "PHP ORM" on the Internet.

Or you can use plain SQL, writing the JOIN and WHERE conditions yourself.