在关联数组中添加值

Question

I'm new to php. This is my code

    $retval = $conn->query("Select points from evaluation_log where session_id='{$sessionid}';");
    $result=array();
    $temp=array();
    while($record = $retval->fetch_array(MYSQLI_ASSOC)) 
        {
            $result[]= $record;
        }

The purpose of this query is to return multiple points against an id from the database which i'm storing in an array. Now I want to take sum of these points in the array. How should I do that.

Answer 1

If you absolutely must use your example then this would work:

$retval = $conn->query("select points from evaluation_log where session_id='{$sessionid}'");

$sum = 0;

while($record = $retval->fetch_array(MYSQLI_ASSOC)) 
{
    $sum+= $record['points'];
}

echo $sum;

---

However, this should be simpler:

$retval = $conn->query("select sum(points) as sum_points from evaluation_log where session_id='{$sessionid}'");

$record = $retval->fetch_array(MYSQLI_ASSOC);

echo $record['sum_points'];