获得指定时间所在月份的天数

PHP: 

$days = cal_days_in_month(CAL_GREGORIAN, 4, 2011);

    echo "返回2011-4的天数 ".$days."<br/>";

    $days = date(‘t‘, strtotime("2011-4-1"));

    echo "返回2011-4的天数 ".$days."<br/>";

    $days = date("t");

    echo "当前月的天数 ".$days."<br/>";

MYSQL:

select DAYOFMONTH(last_day(‘2016-03-26‘));