PHP-计算数据库中表的总年数差异

Question

I would like to calculate the total number of difference in years. The scenario is as follows: I have a table in a database. It contains details of members including their experience in years. I would like to get the total of experience years. For example The total years of experience of members is 90years. So far i have tried and all i get is the experience of just a single member.

public function getMemberCollectiveExperience() {
        global $config;
        $db = new DatabaseController($config['db']['hostname'], $config['db']['username'], $config['db']['password'], $config['db']['database']);
        $sql = "SELECT * FROM tbl_member WHERE status = 1";
        $result = $db->retrieveRecord($sql);
        if ($result->num_rows > 0) {
            while ($row = $result->fetch_array()) {
                #get member years 
                $memberYears = $row['personal_experience'];
                $currentYear = date('Y');
                $firstResult = $currentYear - $memberYears;
                $total = $firstResult;
            }
            $result = array('count' => $total);
        }
        return $result;
    }

Answer 1

You can try this to get the total of all the differences

public function getMemberCollectiveExperience() {
        global $config;
        $total = 0;
        $db = new DatabaseController($config['db']['hostname'], $config['db']['username'], $config['db']['password'], $config['db']['database']);
        $sql = "SELECT * FROM tbl_member WHERE status = 1";
        $result = $db->retrieveRecord($sql);
        if ($result->num_rows > 0) {
            while ($row = $result->fetch_array()) {
                #get member years 
                $memberYears = $row['personal_experience'];
                $currentYear = date('Y');
                $firstResult = $currentYear - $memberYears;
                $total += $firstResult;
            }
            $result = array('count' => $total);
        }
        return $result;
    }