mysql去除重复查询的SQL语句基本思路

浏览数：27 / 时间：2015年06月12日

SELECT R.* FROM trans_flow  R, (SELECT order_no, MAX(status_time) AS status_time FROM trans_flow GROUP BY order_no) S 
WHERE R.order_no = S.order_no AND R.status_time = S.status_time 
ORDER BY R.status_time DESC 

SELECT a.order_no,a.mem_no,c.card_no,c.card_holder,c.bank_name,c.branch_bank_name,a.flag, a.income_type_txt,a.amt,a.create_time FROM account_log a  
JOIN (SELECT b.*,MAX(id) FROM account b GROUP BY b.mem_no) c 
ON DATE_ADD(a.create_time, INTERVAL 7 DAY) < NOW() AND a.`mem_no` = c.mem_no  
ORDER BY a.id DESC

解决思路：
结构如下：
type name guest       date
1   aa       sa           20131101
1   bb      dsf           20131102
1   aa      wew         20131103
我想按照name分组，按照date降序排列，希望的结果如下：
type name guest   date
1   aa       wew     20131103
1   bb       dsf       20131102

select R.* from tab R, (select name, max(date) from tab group by name) S
where R.name=S.name and R.date=S.date
order by R.date desc

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