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mysql-求助一条SQL语句及原理，具体请看描述！
- WBOYOriginal
- 2016-06-06 09:33:281290browse
mysqlsql
如图所示订单表 pid 为null的是主订单
需求是 按主订单ddate倒序排列，子订单排在主订单后面
最终结果如图：
我写的SQL语句可以实现
<code> SELECT DISTINCT id from ( SELECT b.id, a.ddate FROM `tttest` a , `tttest` b where a.id = b.pid union SELECT c.id,c.ddate from tttest c ) t ORDER BY t.ddate desc ,id</code>
但是太复杂 求一条简介的SQL
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