今天再鸿池后面看着他写sql，啪啪啪打了一大串，这么长的一串sql要是我以前看起来根本就是不是我能企及的。可能你们看到我这样说觉得很可笑，个人能力不高，不过贵在努力学习
。
因为之前工作中涉及sql的操作并不多，说起来有些羞愧，这尼玛还好意思舔着脸和别人说工作经验xx年，工作项目xxxxxx。看看人家这写码的素质～，自愧不如啊～
首先，鸿池先在sql工具里写了第一段的sql作为a取出自己需要的字段检查正确性作为a，然后再在sql工具中写另一段sql取出自己需要的字段检查正确性作为b，然后再取出自己需要的字段。
废话不说上代码～～
select a.voucher_value, a.voucher_number as exp_voucher, date(a.issue_time) as exp_issue_date, a.expiry_date as exp_expiry_date
, a.expiry_grace_date as exp_expiry_grace_date
, b.voucher_number as new_voucher, date(a.replace_time) as replace_date
, b.expiry_date as new_expiry_date
, b.expiry_grace_date as new_expiry_grace_date
from (
select a.expired_voucher_id, b.voucher_value, concat(prefix, voucher_text, suffix) as voucher_number,
max(c.action_time) as issue_time, b.expiry_date
, DATE_ADD(b.expiry_date, INTERVAL $this->_grace_period_days DAY) AS expiry_grace_date
, a.replace_time
from $this->_voucher_replace_details a, $this->_voucher b, $this->_voucher_action c
where a.expired_voucher_id = b.voucher_id
and b.voucher_id = c.voucher_id
and c.action_id in ('$issue_action_id', '$issue_action_id2', '$issue_action_id3')
$value_clause
AND (a.replace_time BETWEEN '$quarter_start_date 00:00:00' AND '$quarter_end_date 23:59:59' )
group by b.voucher_id
) a,
(
select a.expired_voucher_id, b.voucher_value, concat(prefix, voucher_text, suffix) as voucher_number,
max(c.action_time) as issue_time, b.expiry_date
, DATE_ADD(b.expiry_date, INTERVAL $this->_grace_period_days DAY) AS expiry_grace_date
from $this->_voucher_replace_details a, $this->_voucher b, $this->_voucher_action c
where a.new_voucher_id = b.voucher_id
and b.voucher_id = c.voucher_id
and c.action_id in ('$issue_action_id', '$issue_action_id2', '$issue_action_id3')
AND (a.replace_time BETWEEN '$quarter_start_date 00:00:00' AND '$quarter_end_date 23:59:59' )
group by b.voucher_id
) b
where a.expired_voucher_id = b.expired_voucher_id
ORDER BY 2 ASC
留念学习，理清逻辑，其实你也可以做到～～