Question

I am coding a movie archive script using codeigniter for myself with PHP. I am getting movie’s information from IMDb and adding them to my database. I’m adding links for movies I selected using another table called links.

This is the query that I am using to get the movies from database:

    $movies = $this->db->query("SELECT *
  FROM movies
  ORDER BY ".$order['by']." ".$order['type']."
  LIMIT ".$limit.", " . $this->config->item('moviePerPage')
  );

and I am fetching it in view file like this:

foreach ($movies->result() as $row) {
  echo $row->name;
}

Now links must be shown for each movie with the matched IDs (movies could have more than one link). My links table has these columns: ‘id’, ‘movieid’, ‘name’, ‘link’

How can I get links for each movie with single MySQL query? Is is posible to get all links that related to current $row movie and bind them to a single variable as array? with this I can loop it with foreach() and show links for each movie.

btw: movies.movieid and links.movieid columns have the same data.

Answer 1

I think you need mysql’s GROUP_CONCAT

Do something like this:-

SELECT 
    movies.*, 
    group_concat(links.link ', ') as links
FROM movies 
LEFT JOIN links 
ON links.movieid = movies.movieid 
GROUP BY movies.movieid

You will get a comma separated list of links for every movie.
Which you can extract like this:-

foreach ($movies->result() as $row) {
  $linksArray = explode(",",$row->links);
}

Updates
I think this is the only way you can get the results without having multiple result rows for a single movie with multiple links.

Just be careful of the maximum length of characters you can get in the result – by default 1024 characters. Read this
Mysql group_concat_max_length and Group concat max length to know how to override the limit.

And like Dan Grossman has poined out, if you feel the links may contain comma, use a different or uncommon delimiter.