I keep getting double results. - php

Question

I am an amateur programmer, and I just don't know what's wrong with my query. I want to get stuff out of the database for my landing page, but if I have multiple genres, I get multiple results. I think it has something to do with my query. Bear in mind, I'm not good at programming, nor am I good at SQL I have a table with films called 'films', the primary key is 'id', the table 'genres' has 'genreid' as primary key, and 'filmgenre' (where I inner join) has 'filmgenreid' as primary key. My code:
<?php
if(isset($_GET["id"])){
$filmid = $_GET["id"];
$query = mysqli_query($con, "SELECT *
FROM filmgenre INNER JOIN genres ON
genres.genreid=filmgenre.genreid INNER JOIN
films ON films.id=filmgenre.id WHERE films.id = '$filmid'");
while($film = mysqli_fetch_array($query)){
?>
<img class="filmimage" src="<?php echo $film["plaatje"] ?>" />
<h2 class="filmtitle"><?php echo $film["titel"] ?></h2><br>
<p class="tijdsduur">Tijdsduur: <?php $film["tijdsduur"] ?> minuten.</p>
<iframe width="854" height="480" src="<?php echo $film["trailer"] ?>" frameborder="0" allowfullscreen></iframe>
<p class="beschrijving"> <?php echo $film["voorwoord"] ?></p>
<p class="producent">Producent <?php echo $film["producent"] ?>.</p>
<p class="auteurs">Auteurs: <?php echo $film["auteurs"] ?>.</p>
<p class="jaar"><?php echo $film["jaar"] ?>.</p>
<?php echo $film["hoofdpersonen"] ?>
<?php
}
}
else{
echo "Something went wrong.";
}
?>
Can anyone help?

Answer 1

Use group by,
WHERE films.id = '$filmid'" group by films.id;

Answer 2

Cant really understand what you want exactly but could you give an example of what you should expect plus what you are getting instead
SELECT * FROM filmgenre fg INNER JOIN genres g ON fg.genreid =g.genreid
INNER JOIN films f ON fg.id = f.id WHERE f.id = '$filmid' GROUP BY g.genreid";