Question

我正在尝试检索已超过某个事件的表格中的最新条目。此关注的主表包含用户的ID，发生的事件类型以及时间戳。

这就是我目前所在的地方：

function playBeep() {
  var sound = document.getElementById("Sound")
  sound.play();
  window.location.href = '/'; //Go to HomePage

}

这个输出给了我以前的所有事件（虽然没有针对个别事件的欺骗，我假设）。我现在正在寻找一种方法来获取RefNo，Subcase，EventDate和EventCode的每个组合的最新版本。

Answer 1

未经测试，但与WITH TIES一致的Row_Number()条款可能会对此有所帮助

SELECT Top 1 with ties
       cc.RefNo
      ,cc.Subcase
      ,ev.EventDate 
      ,evt.EventCode
      ,ev.Amount
      ,previousevent.EventCode as [previous Event]
      ,previousevent.previousdate as [date previous event]
  FROM event ev JOIN EventTemplate evt ON ev.EventTemplateID = evt.ID
  JOIN CCase cc ON cc.ID = ev.CCaseID 
  JOIN (SELECT MAX(ev.EventDate) as previousdate, evt.EventCode, CCaseID
                            FROM Event ev JOIN EventTemplate evt ON ev.EventTemplateID = evt.ID
                            WHERE (evt.EventCode LIKE 'SI%' OR evt.EventCode LIKE 'SM%')
                            Group by CCaseID, evt.EventCode) as previousevent
  ON previousevent.CCaseID = cc.ID
  AND previousevent.previousdate < ev.EventDate
  Order By Row_Number() over (Partition By RefNo, Subcase, EventCode Order By EventDate Desc)

Answer 2

可能最简单的方法是使用cte和row_number：

;WITH CTE AS
(
    SELECT cc.RefNo
        ,cc.Subcase
        ,ev.EventDate 
        ,evt.EventCode
        ,ev.Amount
        ,previousevent.EventCode as [previous Event]
        ,previousevent.previousdate as [date previous event]
        , ROW_NUMBER() OVER (PARTITION BY cc.RefNo ,cc.Subcase ,ev.EventDate, evt.EventCode ORDER BY previousevent.previousdate DESC) AS rn
      FROM event ev JOIN EventTemplate evt ON ev.EventTemplateID = evt.ID
      JOIN CCase cc ON cc.ID = ev.CCaseID 
      JOIN (SELECT MAX(ev.EventDate) as previousdate, evt.EventCode, CCaseID
                                FROM Event ev JOIN EventTemplate evt ON ev.EventTemplateID = evt.ID
                                WHERE (evt.EventCode LIKE 'SI%' OR evt.EventCode LIKE 'SM%')
                                Group by CCaseID, evt.EventCode) as previousevent
      ON previousevent.CCaseID = cc.ID
      AND previousevent.previousdate < ev.EventDate
)

SELECT cc.RefNo
        ,cc.Subcase
        ,ev.EventDate 
        ,evt.EventCode
        ,ev.Amount
        ,previousevent.EventCode as [previous Event]
        ,previousevent.previousdate as [date previous event]
FROM CTE
WHERE rn = 1

尝试检索表中最近的上一个条目

2 个答案: