批量 MySQL 更新而不是 PHP While 循环

Question

I am using PHP code to update week ending date which is on a different day for each subdomain. Each subdomain date range varies.

My current code uses a while loop to update the week end date. This is very slow and I am looking for ideas to optimise it.

Here is my current code:

// Loop through and assign week end date to each user activity.
$nextWeek = $startDate;  // initialise while loop condition
while ($nextWeek <= $endDate) {
    $lastWeek = $nextWeek;
    $nextWeek = Carbon::parse($lastWeek)->addWeek(1)->format('Y-m-d');

    // update activity date to week end date
    $query = 'UPDATE r_active_user_activities 
                SET week_end_date = "' . $nextWeek . '"
                WHERE (activity_date > "' . $lastWeek . '" 
                    AND activity_date <= "' . $nextWeek . '"  
                    AND subdomain="' . $subdomain->subdomain . '" );';
    $db->statement($query);
}

Answer 1

Just append all those update queries in a php variable ($query) and execute that outside the while loop. something like this.

$nextWeek = $startDate;  // initialise while loop condition
$query = '';
while ($nextWeek <= $endDate) {
$lastWeek = $nextWeek;
$nextWeek = Carbon::parse($lastWeek)->addWeek(1)->format('Y-m-d');

// update activity date to week end date
$query .= 'UPDATE r_active_user_activities 
            SET week_end_date = "' . $nextWeek . '"
            WHERE (activity_date > "' . $lastWeek . '" 
                AND activity_date <= "' . $nextWeek . '"  
                AND subdomain="' . $subdomain->subdomain . '" );';
 }
$db->statement($query);