PHP Sort an array - php

Question

I have an array
$genreQuery = $con ->query ("select distinct(movie_year) from movies");
$movieGenre = array();
$movieTitle = array();
$movieList = array();
while($row = $genreQuery->fetch_object()) {
$movieGenre[] = $row;
}
foreach($movieGenre as $MGenre){
$query = $con ->query
("
select '$MGenre->movie_year' movie_year, IFNULL(count(*)/(select count(*)
from user_movie_ratings where user_id = '$userid'),0) rating
from user_movie_ratings umr,
movies m
where umr.user_id = '$userid'
and umr.movie_id = m.id
and m.movie_year = '$MGenre->movie_year' ORDER BY rating DESC;
");
while($row = $query->fetch_object()) {
$movieTitle[] = $row;
}
}
$text = "";
foreach($movieTitle as $MTitle){
if (empty($text)){
$text = "\"".$MTitle->movie_year."\"";}
else{
$text = $text.",\"".$MTitle->movie_year."\"";
}
}
$list = $con ->query
("
SELECT movie_name, avg_rating, image, id, genre
FROM movies
WHERE id NOT IN (SELECT movie_id FROM user_movie_ratings WHERE user_id = '$userid')
ORDER BY field(movie_year, $text), avg_rating DESC;
");
while($row = $list->fetch_object()) {
$movieList[] = $row;
}
The array is filled by the above query, what I want to do is sort it by the rating so that is looks like this
year rating
2014 0.0001
2015 0.0000
2013 0.0000
1967 0.0000
.... ......
.... ......
etc etc
I have tried adding ORDER BY rating DESC to the query, but that does not work and when I use rsort($movieTitle) it sorts by the year not the rating do I need to do some kind of multidimensional sort, or is there another way?

Answer 1

I would guess that ordering by rating does not work as you seem to be running multiple queries in a foreach loop and each iteration gets one year. So in that case, your order would be by year and then in the year by rating.
You should get rid of that loop and only do one query and then the condition and sort order would be:
...
AND m.movie_year IN (the,years,you,want)
ORDER BY rating DESC
By looping over the $movieGenre like you do now, you can easily generate a comma separated list for the years to use in the IN statement.
Edit: Based on your comment you want all years, so the foreach loop and the year condition in the query are unnecessary.
You probably want something like:
SELECT m.movie_year, IFNULL(count(*)/(select count(*)
from user_movie_ratings where user_id = '$userid'),0) rating
FROM user_movie_ratings umr,
movies m
WHERE umr.user_id = '$userid'
AND umr.movie_id = m.id
ORDER BY rating DESC
Assuming of course that the user ID is safe to use in a query, you should really use a prepared statement to avoid potential sql injection.
Now you have all your results in one query so there is no need for the outer loop any more.