Altering a query to not duplicate data - php

Question

In my database, I have 3 tables.
Jokes:
CREATE TABLE IF NOT EXISTS `jokes` (
`joke_id` int(11) NOT NULL AUTO_INCREMENT,
`joke` varchar(1024) NOT NULL,
`category_id` int(11) NOT NULL,
`vote` int(255) NOT NULL,
`date_added` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
PRIMARY KEY (`joke_id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ;
Category:
CREATE TABLE IF NOT EXISTS `category` (
`category_id` int(11) NOT NULL AUTO_INCREMENT,
`name` varchar(51) NOT NULL,
PRIMARY KEY (`category_id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ;
And finally, Comments:
CREATE TABLE IF NOT EXISTS `comments` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`name` varchar(40) NOT NULL,
`comment` text NOT NULL,
`joke_id` int(11) NOT NULL,
`post_id` int(11) NOT NULL,
`date` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ;
This function is stored in my read controller, with the name of Joke and it grabs the data from the db then sends it to the view.
public function joke($joke_id = FALSE)
{
if ($joke_id === FALSE) redirect('main'); //go to default controller
$data['results'] = $this->comments_m->getComments($joke_id, $this->uri->segment(2));
$this->load->view('template/header');
$this->load->view('template/sidebar');
$this->load->view('content/read', $data);
$this->load->view('template/footer');
}
The model (getjokes_m) has a function called readJokes which gets the joke, joke_id, category name, votes, comments. This function is used to read specific jokes in the database.
function readJokes($joke_id)
{
$query = $this->db->query("SELECT c.name, j.*, co.* FROM jokes j LEFT JOIN category c ON c.category_id = j.category_id LEFT JOIN comments co ON co.joke_id = j.joke_id WHERE j.joke_id = '$joke_id'") or die("No results found" );
//displays the results
return $query->result();
}
The query above is where the problem lies. For the moment it returns the joke as many times as the joke has been commented. I.e if the joke has 6 comments, the joke will show 6 times (no idea why). Any help altering this query, to just show the joke once, with all the comments the joke has, will be much appreciated.

Answer 1

You want a group by with group_concat() for the comments:
SELECT c.name, j.*, group_concat(co.comment separator '|') as comments
FROM jokes j LEFT JOIN
category c
ON c.category_id = j.category_id LEFT JOIN
comments co
ON co.joke_id = j.joke_id
WHERE j.joke_id = '$joke_id'
GROUP BY j.joke_id;
Actually the group by is not strictly needed here, unless you want to get the results for more than one joke.