Why doesnt this update update the score?

Question

I am trying to create an update that whenever the user gets an offer lower than the last day/week average price they get points for it 50 for last day and 20 for last week

I am desperate I have been trying for the longest time to chage thing on the proyect and now when I try to update that for every time the condition is met to update the db, it does its work and see when the price is cheaper and where it isnt but never increases the score which bugs me a lot¿can someone help?

function check_if_offer_cheaper_with_twenty_than_previous_day($prodname, $price)
// Check if the price found by the user is 20% lower than the most recent available average price of the previous day
{
    global $db;
    $sql = 'SELECT AVG(prices.price) >"' . $price /  0.8 . '" AS cheaper_than_previous_day'
        . " FROM prices"
        . ' WHERE prices.prodname = "' . $prodname . '"' .
        ' AND prices.date = CURDATE() - INTERVAL 1 DAY';


    $result = mysqli_query($db, $sql);
    $row = mysqli_fetch_assoc($result);

    if (isset($row['cheaper_than_previous_day'])) {
        $query = "UPDATE users SET total_score = total_score +50,
        score_this_month = score_this_month + 50 WHERE id = '" . $_SESSION['user']['id'] . "'";
        mysqli_query($db, $query);
        return $row['cheaper_than_previous_day'];
    } else {
        return true;
    }
}

function check_if_offer_cheaper_with_twenty_than_previous_week($prodname, $price)
// Check if the price found by the user is 20% lower than the most recent average price available in the previous week
{
    global $db;
    $sql = 'SELECT AVG(prices.price) > "' . $price / 0.8 . '" AS cheaper_than_previous_week'
        . " FROM prices"
        . ' WHERE prices.prodname = "' . $prodname .
        '" AND prices.date BETWEEN CURDATE() - INTERVAL 8 DAY AND CURDATE() - INTERVAL 1 DAY';

    $result = mysqli_query($db, $sql);
    $row = mysqli_fetch_assoc($result);

    if (isset($row['cheaper_than_previous_week'])) {
       $query = "UPDATE users SET total_score = total_score +20, score_this_month = score_this_month +50           
       WHERE id = '" . $_SESSION['user']['id'] . "'";
        mysqli_query($db, $query);
        return $row['cheaper_than_previous_week'];
    } else {
        
        return true;
    }
}

Answer 1

MySQL syntax uses commas to separate the assignment pairs, like this

       $query = "UPDATE users SET total_score = total_score +20, 
                 score_this_month = score_this_month +50
                 WHERE id = '" . $_SESSION['user']['id'] . "'";           

dev.mysql 8.0 update syntax

That is assuming that $_SESSION['user']['id'] does not evaluate to null.