mysql查询指定时间，数据库时间戳

数据库时间戳字段：create_time

$_POST['other_time']：自定义时间格式20200620

$link = Db::link();
$sql = "SELECT * FROM `order` where 1=1";
/*时间范围*/
if($search_data['search_time_start_to_end'] == 'today'){
    $sql .= " AND  to_days(FROM_UNIXTIME(create_time,'%Y%m%d')) = to_days(now())";//当日数据
}

if($search_data['search_time_start_to_end'] == 'yesterday'){
    $sql .= " AND TO_DAYS(NOW())- TO_DAYS(FROM_UNIXTIME(create_time,'%Y%m%d')) = 1 ";//昨天数据
}

if($search_data['search_time_start_to_end'] == 'week'){
    $sql .= " AND DATE_SUB(CURDATE(), INTERVAL 7 DAY) <= date(FROM_UNIXTIME(create_time,'%Y%m%d')) ";//7天数据
}

if($search_data['search_time_start_to_end'] == 'month'){
    $sql .= " AND DATE_FORMAT(FROM_UNIXTIME(create_time,'%Y%m%d'), '%Y%m' ) = DATE_FORMAT(CURDATE() , '%Y%m' )";//本月
}

if($search_data['search_time_start_to_end'] == 'last_month'){
    $sql .= " AND PERIOD_DIFF(date_format(now(),'%Y%m') , date_format(FROM_UNIXTIME(create_time,'%Y%m%d'),'%Y%m')) = 1 ";//上月
}

if($search_data['search_time_start_to_end'] == 'other_time'){
    $sql .= " AND FROM_UNIXTIME(create_time,'%Y%m%d') ='".$_POST['other_time']."' ";//指定年月日
}
/*时间范围结束*/

$sql .= " ORDER BY create_time DESC ";
$result = $link->query($sql);
$rows = $result->fetch_all(MYSQLI_ASSOC);