Question

我有3张牌桌：opportunities，tr_opportunity_updates和
opportunities_tr_opportunity_updates_1_c。后者将opportunities与opportunity_updates联系起来。

我想获得3列，第一列是机会名称，第二列是对机会进行的最后更新，第三列是对机会进行的第二次更新。

我想获得以下输出：

  -----------------------------------------------
  Opportunity | Last_Update | Second_Last update 
  -----------------------------------------------
  Opp1        | update      | second bla bla     
  -----------------------------------------------
  Opp2        | Lastest up. | second bla bla

我有一个获取商机名称和最后更新的查询，但我不知道如何获得第二次更新，并将其作为另一列添加。这是一个子查询吗？如果是这样的话：

  SELECT opportunities.name AS Opportunity, tr_opportunity_updates.description AS Last_Update
  FROM opportunities
  LEFT JOIN opportunities_tr_opportunity_updates_1_c ON opportunities_tr_opportunity_updates_1_c.opportunities_tr_opportunity_updates_1opportunities_ida = opportunities.id
  LEFT JOIN tr_opportunity_updates ON opportunities_tr_opportunity_updates_1_c.opportunities_tr_opportunity_updates_1tr_opportunity_updates_idb = tr_opportunity_updates.id
  WHERE opportunities.deleted = 0
  GROUP BY opportunities.name
  LIMIT 0 , 30

我试图为此实现一个sql小提琴，但是我的表格和数据都很大，有许多不敬的字段，但除了date_created之外，所有与上述问题相关的信息除了所有表中的date_created之外都可能需要获取第二次更新？

Answer 1

由于没有人试图提供帮助，我会发布自己的答案：

 SELECT oppa.name AS Opportunity, tr_opportunity_updates.description AS Last_Update,
 (SELECT tou.description FROM opportunities oppb
 LEFT JOIN opportunities_tr_opportunity_updates_1_c ON opportunities_tr_opportunity_updates_1_c.opportunities_tr_opportunity_updates_1opportunities_ida = oppb.id LEFT JOIN tr_opportunity_updates tou ON opportunities_tr_opportunity_updates_1_c.opportunities_tr_opportunity_updates_1tr_opportunity_updates_idb = tou.id
 WHERE oppb.deleted =0 AND tou.deleted =0 AND oppb.id = oppa.id
 ORDER BY tou.date_modified Desc LIMIT 1,1) AS Second_Last_Update
 FROM opportunities oppa
 LEFT JOIN opportunities_tr_opportunity_updates_1_c ON opportunities_tr_opportunity_updates_1_c.opportunities_tr_opportunity_updates_1opportunities_ida = oppa.id
 LEFT JOIN tr_opportunity_updates ON opportunities_tr_opportunity_updates_1_c.opportunities_tr_opportunity_updates_1tr_opportunity_updates_idb = tr_opportunity_updates.id
 WHERE oppa.deleted =0 AND tr_opportunity_updates.deleted =0
  GROUP BY oppa.name

如何获取上次相关更新和第二次相关更新

1 个答案: