get date format in year and month

//get the month only in php
$date = DateTime::createFromFormat('Y-m-d', $conver_month);
$conver_month = $date->format('Y-m');

//get the month only in mysql
where  fsd.fs_sec_id = $sec_id  and date_format(cth.th_trandate,'%Y-%m') = '$month'