LEFT JOIN in ZF2 using TableGateway

Question

I have a table:

*CREATE TABLE IF NOT EXISTS `blogs_settings` (
  `blog_id` int(11) NOT NULL AUTO_INCREMENT,
  `owner_id` int(11) NOT NULL,
  `title` varchar(255) NOT NULL,
  `meta_description` text NOT NULL,
  `meta_keywords` text NOT NULL,
  `theme` varchar(25) NOT NULL DEFAULT 'default',
  `is_active` tinyint(1) NOT NULL DEFAULT '1',
  `date_created` int(11) NOT NULL,

  PRIMARY KEY (`blog_id`),
  KEY `owner_id` (`owner_id`)
) ENGINE=InnoDB  DEFAULT CHARSET=utf8 AUTO_INCREMENT=2 ;*

And the second table:

*CREATE TABLE IF NOT EXISTS `users` (
  `user_id` int(11) NOT NULL AUTO_INCREMENT,
  `username` varchar(255) NOT NULL,
  `email` varchar(255) NOT NULL,
  `password` varchar(128) NOT NULL,
  `sex` tinyint(1) NOT NULL,
  `birthday` date NOT NULL,
  `avatar_id` int(11) DEFAULT NULL,
  `user_level` tinyint(1) NOT NULL DEFAULT '1',
  `date_registered` int(11) NOT NULL,
  `is_active` tinyint(1) NOT NULL DEFAULT '0',
  `is_banned` tinyint(1) NOT NULL DEFAULT '0',

  PRIMARY KEY (`user_id`),
  KEY `is_active` (`is_active`),
  KEY `user_level` (`user_level`),
  KEY `is_banned` (`is_banned`),
  KEY `username` (`username`)
) ENGINE=InnoDB  DEFAULT CHARSET=utf8 AUTO_INCREMENT=2 ;*

How may I select all the fields from blogs_settings table and join only the 'username' field from the users table using TableGateway in ZF2, on blogs_settings.owner_id = users.user_id. Thanks in advance. Your help is much appreciated.

EDIT:

namespace Object\Model;

use Zend\Db\TableGateway\TableGateway;
use Zend\Db\Sql\Select;

class BlogsSettingsTable {

protected $tableGateway;
protected $select;

public function __construct(TableGateway $tableGateway) {
    $this->tableGateway = $tableGateway;
    $this->select = new Select();
}

public function getBlogs($field = '', $value = '') {
    $resultSet = $this->tableGateway->select(function(Select $select) {
                $select->join('users', 'blogs_settings.owner_id = users.user_id', array('username'));
            });

    return $resultSet;
}

public function getBlog($blogID) {
    $id = (int) $blogID;

    $rowset = $this->tableGateway->select(array('blog_id' => $id));
    $row = $rowset->current();

    if (!$row) {
        throw new Exception('Could not find row with ID = ' . $id);
    }

    return $row;
}

public function addBlog(BlogsSettings $blog) {
    $data = array(
        'owner_id' => $blog->owner_id,
        'title' => $blog->title,
        'meta_description' => $blog->meta_description,
        'meta_keywords' => $blog->meta_keywords,
        'theme' => $blog->theme,
        'is_active' => $blog->is_active,
        'date_created' => $blog->date_created,
    );

    $this->tableGateway->insert($data);
}

public function deleteBlog($blogID) {
    return $this->tableGateway->delete(array('blog_id' => $blogID));
}

}

With this, it executes the following query:

SELECT blogs_settings.*, users.username AS username FROM blogs_settings INNER JOIN users ON blogs_settings.owner_id = users.user_id

but the resultSet does not contain the username field from the joined 'users' table. However, when I run the query in phpmyadmin, everything is okay and I have the 'username' field from the 'users' table joined. What's the problem?

EDIT 2 ok, I now tried the following:

public function getBlogs() {
    $select = $this->tableGateway->getSql()->select();
    $select->columns(array('blog_id', 'interest_id', 'owner_id', 'title', 'date_created'));
    $select->join('users', 'users.user_id = blogs_settings.owner_id', array('username'), 'left');

    $resultSet = $this->tableGateway->selectWith($select);

    return $resultSet;
}

the executed query is:

SELECT `blogs_settings`.`blog_id` AS `blog_id`, `blogs_settings`.`interest_id` AS `interest_id`, `blogs_settings`.`owner_id` AS `owner_id`, `blogs_settings`.`title` AS `title`, `blogs_settings`.`date_created` AS `date_created`, `users`.`username` AS `username` FROM `blogs_settings` LEFT JOIN `users` ON `users`.`user_id` = `blogs_settings`.`owner_id`

When I run it into phpmyadmin, it joins the username field from the users table. When in zf2, it doesn't.

Here's the dump of the whole object:

Zend\Db\ResultSet\ResultSet Object
(
[allowedReturnTypes:protected] => Array
    (
        [0] => arrayobject
        [1] => array
    )

[arrayObjectPrototype:protected] => Object\Model\BlogsSettings Object
    (
        [blog_id] => 
        [interest_id] => 
        [owner_id] => 
        [title] => 
        [meta_description] => 
        [meta_keywords] => 
        [theme] => 
        [is_active] => 
        [date_created] => 
    )

[returnType:protected] => arrayobject
[buffer:protected] => 
[count:protected] => 1
[dataSource:protected] => Zend\Db\Adapter\Driver\Pdo\Result Object
    (
        [statementMode:protected] => forward
        [resource:protected] => PDOStatement Object
            (
                [queryString] => SELECT `blogs_settings`.`blog_id` AS `blog_id`, `blogs_settings`.`interest_id` AS `interest_id`, `blogs_settings`.`owner_id` AS `owner_id`, `blogs_settings`.`title` AS `title`, `blogs_settings`.`date_created` AS `date_created`, `users`.`username` AS `username` FROM `blogs_settings` LEFT JOIN `users` ON `users`.`user_id` = `blogs_settings`.`owner_id`
            )

        [options:protected] => 
        [currentComplete:protected] => 
        [currentData:protected] => 
        [position:protected] => -1
        [generatedValue:protected] => 0
        [rowCount:protected] => 1
    )

[fieldCount:protected] => 6
[position:protected] => 
)

Up... any ideas?

Answer 1

Adding to @samsonasik's answer and addressing the issues in its comments. You won't be able to get the joined values out of what is returned from that statement. That statement returns the model object which won't have the joined rows. You'll need to execute it as SQL at a level which will prepare it as raw SQL and return you each resulting row as an array rather than an object:

$sqlSelect = $this->tableGateway->getSql()->select();
$sqlSelect->columns(array('column_name_yourtable'));
$sqlSelect->join('othertable', 'othertable.id = yourtable.id', array('column_name_othertable'), 'left');

$statement = $this->tableGateway->getSql()->prepareStatementForSqlObject($sqlSelect);
$resultSet = $statement->execute();
return $resultSet;

//then in your controller or view:

foreach($resultSet as $row){
    print_r($row['column_name_yourtable']);
    print_r($row['column_name_othertable']);
}

Answer 2

if you're using TableGateway, you can select join like this

$sqlSelect = $this->tableGateway->getSql()->select();
$sqlSelect->columns(array('column_name'));
$sqlSelect->join('othertable', 'othertable.id = yourtable.id', array(), 'left');

$resultSet = $this->tableGateway->selectWith($sqlSelect);
return $resultSet;