Check if database contains string

photo database

Here is my code:

$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
} 

if (isset($_POST['ingredienten']) && !empty($_POST['ingredienten'])) {
    foreach ($_POST['ingredienten'] as $ingredienten) {

    }                           

}
echo $fruitList = implode('', $_POST['ingredienten']);

}


$sql = "SELECT * FROM keuzes, keuzes2, keuzes3, keuzes4, register, gerechten WHERE gerechten.IDpersoon = $test AND gerechten.ingredienten1 LIKE '%" . $fruitList . "%' AND gerechten.ingredienten1 = keuzes.ID AND gerechten.ratings = keuzes3.ID AND gerechten.tijdsduren = keuzes2.ID AND gerechten.maaltijden1 = keuzes4.ID AND gerechten.IDpersoon = register.ID";

$result = $conn->query($sql);
    if ($result->num_rows > 0) {
        // output data of each row
        while($row = $result->fetch_assoc()) {

        }
} else {

}
$conn->close();
}

I want to check if the string: "$fruitList", contains in the database, but it isn't working.

Can someone help me please?