I have setup an query where it selects multiple things.
$stm = $db->query(\'SELECT startUser, forUser, percentage, time, taskTitle, taskDesc, color FROM a
If it truly is a JSON field, in 5.7 you can do this:
SELECT startUser, forUser, percentage, time, taskTitle, taskDesc, color FROM admin_task WHERE JSON_CONTAINS(forUser->'$[*]', JSON_ARRAY("somestring"))