Question

我有一张记录事件的表：

create table #events
(  intRowId int identity(1,1),
   intItemId int,
   intUserId int,
   datEvent datetime)

这是一张拥有数百万行的大桌子，可记录数千件物品和成千上万用户的活动。

我想要查找一个包含10个itemID的选择组，但只有当它们以某种模式出现时：我正在尝试查找所有这些项目中的所有项目都针对相同的userID注册的事件并关闭和时在一起，说5分钟。

我绝对没有想法如何解决这个问题。人们会认为分区涉及到某个地方，但是，即使只是某个地方的帮助，也会非常感激。

干杯，马特

Answer 1

让我们说你想要关于物品ID的统计数据：1,2，...，10。首先创建一个表EventByItems：

CREATE TABLE EventByItems
(  
   intRowId int identity(1,1),   
   intUserId int,
   datEvent datetime,
   intItem1 int,
   intItem2 int,
   intItem3 int,
   ...
   intItem10 int
)

然后使用query填充此表：

SELECT intUserId, datEvent, 
   SUM(pvt.[1]), SUM(pvt.[2]), SUM(pvt.[3]), ... , SUM(pvt.[10])
FROM #events
PIVOT
(
    COUNT(intItemId)
    FOR intItemId IN ([1], [2], [3], ... , [10])
) AS pvt
GROUP BY intUserId, datEvent

现在我们可以使用该表做一些工作。例如，我们可以根据您的逻辑更新它以填补空白。或者我们可以这样做：

SELECT
  intRowId,
  intUserId,
  datEvent
FROM
  EventByItems AS E
WHERE
  ((intItem1 > 0) OR EXISTS(SELECT * 
                            FROM EventByItems 
                            WHERE intUserId = E.intUserId
                             AND intItem1 > 0
                             AND DATEDIFF(MINUTE, datEvent, E.datEvent) <= 5
                             AND intRowId != E.intRowId ))
  AND

  ...

  AND
  ((intItem10 > 0) OR EXISTS(SELECT * 
                            FROM EventByItems 
                            WHERE intUserId = E.intUserId
                             AND intItem10 > 0
                             AND DATEDIFF(MINUTE, datEvent, E.datEvent) <= 5
                             AND intRowId != E.intRowId ))

Answer 2

好的，下面你会找到一个可以满足你想要的工作示例。我假设事件不必出现在十位。

但解决方案非常粗糙，并且运行缓慢，特别是如果您增加了项目数/用户数。无论如何，请不要为此向我投降太多，我希望你能找到一个合适的解决方案:)。

具有预先选择的事件的临时表将有助于我的解决方案中的性能，但您真正需要的是窗口函数，例如在Oracle中。

DROP TABLE #events
GO

create table #events
(  intRowId int identity(1,1),
   intItemId int,
   intUserId int,
   datEvent datetime)
 GO 

insert into #events (intUserId,intItemId,  datEvent)
select '1','1','2013-05-01 10:25' union all --group1
select '1','2','2013-05-01 10:25' union all --group1
select '1','3','2013-05-01 10:26' union all --group1
select '1','7','2013-05-01 10:25' union all
select '1','8','2013-05-01 10:25' union all
select '1','9','2013-05-01 10:26' union all
select '1','1','2013-05-01 10:50' union all --group2
select '1','2','2013-05-01 10:52' union all --group2
select '1','3','2013-05-01 10:59' union all 
select '1','1','2013-05-01 11:10' union all --group3
select '1','1','2013-05-01 11:12' union all --group3
select '1','3','2013-05-01 11:17' union all --group3
select '1','2','2013-05-01 11:25' union all
select '1','1','2013-05-01 11:31' union all
select '1','7','2013-05-01 11:32' union all
select '1','2','2013-05-01 11:50' union all --group4
select '1','2','2013-05-01 11:50' union all --group4
select '1','3','2013-05-01 11:50' union all --group4
select '1','1','2013-05-01 11:56'
GO 

DROP TABLE #temp
GO
select 
     e1.intRowId as intRowId_1, e1.intItemId as intItemId_1, e1.intUserId as intUserId_1, e1.datEvent as datEvent_1
    ,e2.intRowId as intRowId_2, e2.intItemId as intItemId_2, e2.intUserId as intUserId_2, e2.datEvent as datEvent_2
into #temp
from #events e1
join #events e2
    on e1.intUserId=e2.intUserId
    and e1.datEvent<=e2.datEvent
    and e1.intRowId<>e2.intRowId
where 1=1
    and e1.intUserId=1
    and e2.intUserId=1
    and e1.intItemId in (1,2,3)
    and e2.intItemId in (1,2,3)
    and datediff(minute,e1.datevent,e2.datevent)<6
order by 
    e1.intRowId, e2.intRowId
GO

select distinct
    * 
from (
    select 
        intRowId_1 as intRowId, intItemId_1 as intItemId, intUserId_1 as intUserId, datEvent_1 as datEvent
    from #temp

    UNION ALL

    select 
        intRowId_2 as intRowId, intItemId_2 as intItemId, intUserId_2 as intUserId, datEvent_2 as datEvent
    from #temp
) x
order by 
    datEvent, intRowId

查找群集数据点组

2 个答案: