基于特定条件的最大日期的返回记录

Question

我试图从包含“活动”的客户表中编写查询。每个活动存储在一行中，因此如果您调用联系人并发送电子邮件后，它将分为两行。

即

Contact Employee Date    Method 
Jack John  12/7/15 11:50  Email 
Jack John  12/7/15 11:45  Email 
Jill John  12/4/15 10:19  Call 
Rick Amber  12/8/15 9:40  Call 
Dave Sarah  12/10/15 17:10 Email 
Dave Sarah  12/10/15 17:15 Call 
Dave Sarah  12/10/15 17:20 Email 

我想回到最近的记录呼叫，如果没有呼叫，那么最近的电子邮件。

所以输出将返回这样的：

Contact Employee Date    Method 
Jack John  12/7/15 11:50  Email 
Jill John  12/4/15 10:19  Call 
Rick Amber  12/8/15 9:40  Call 
Dave Sarah  12/10/15 17:15 Call 

这是我写的当前查询：

select FA.ContactID, 
FA.Employee as [ContactedBy], 
FA.CreatedDate as [ContactedDate], 
case when max(FA.CreatedDate) and FA.PrincipalCall = 1 then 'Call' 
    when max(FA.CreatedDate) and FA.PrincipalCall = 0 and FA.InboundEmail = 1 then 'Call & Email' 
    end as [ContactMethod] 

from WorkingData.dbo.FactActivities FA 

where FA.CreatedDate >= CAST('12-04-2015' as date) 
and (FA.PrincipalCall = 1 or FA.InboundEmail = 1) 

任何想法吗？

Answer 1

的row_number窗口功能可以帮助在这里：

select t.contact, t.employee, t.date, t.method 
    from (select *, 
       row_number() over (partition by contact, employee 
            order by 
            case when method = 'Call' then 0 else 1 end, 
            date desc) as rn 
      from WorkingData.dbo.FactActivities) t 
where t.rn = 1 

根据您想要的结果，我假设你正在寻找最新的call/email记录每contact/employee组合。如果这不完全正确，则只需在查询中调整partition by子句。

Answer 2

感谢sstan;这是我完成了：

select t.ContactID, t.Priority, t.ContactedBy, t.ContactedDate, t.ContactMethod 

from (select FA.ContactID, 
    case when FA.PriorityLevel is null then 2 else FA.PriorityLevel end as [Priority], 
    FA.Employee as [ContactedBy], 
    FA.CreatedDate as [ContactedDate], 
    case when FA.PrincipalCall = 1 then 'Call' 
     when FA.InboundEmail = 1 then 'Email' 
     when FA.PrincipalCall = 1 and FA.InboundEmail = 1 then 'Call & Email' 
     end as [ContactMethod], 
    row_number() over (partition by FA.ContactID 
           order by case when FA.PrincipalCall = 1 then 0 else 1 end, 
           FA.CreatedDate desc) as rn 
     from WorkingData.dbo.FactActivities FA 

     where FA.CreatedDate >= CAST('12-04-2015' as date) 
      and (FA.PrincipalCall = 1 or FA.InboundEmail = 1)) t 
where t.rn = 1 

也无所谓谁的员工是进行的接触，只是接触与名单上的个人做出，所以我删除了从分区

Answer 3

考虑一个没有窗口函数的UNION查询。下面按数据版本类型细分，因为您发布的版本与实际数据不完全匹配。

你简化发布的数据版本：

-- AGGREGATE FOR CALLS 
SELECT TableName.Contact, TableName.Employee, 
     Max(TableName.Date) AS MaxOfDate, TableName.Method 
FROM TableName 
WHERE TableName.Method = 'Call' 
GROUP BY TableName.Contact, TableName.Employee, 
     TableName.Method 
UNION 

-- AGGREGATE FOR EMAILS (WITH NO CALLS) 
SELECT TableName.Contact, TableName.Employee, 
     Max(TableName.Date) AS MaxOfDate, TableName.Method  
FROM TableName 
WHERE TableName.Method = 'Email' 
GROUP BY TableName.Contact, TableName.Employee, 
     TableName.Method 
HAVING (SELECT Count(*) 
     FROM TableName t2 
     WHERE t2.Method = 'Call' 
     AND t2.Contact = TableName.Contact 
     AND t2.Employee = TableName.Employee) = 0 

---

实际数据版本（可能需要调整）：

-- AGGREGATE FOR CALLS 
SELECT FA.ContactID, 
     FA.Employee AS [ContactedBy], 
     Max(FA.CreatedDate) AS [ContactedDate], 
     'Call' AS [ContactMethod]  
FROM WorkingData.dbo.FactActivities FA 
WHERE FA.PrincipalCall = 1 AND FA.CreatedDate >= CAST('12-04-2015' as date) 
GROUP BY FA.ContactID, 
     FA.Employee 
ORDER BY FA.ContactID 

UNION 

-- AGGREGATE FOR EMAILS (WITH NO CALLS) 
SELECT FA.ContactID, 
     FA.Employee AS [ContactedBy], 
     Max(FA.CreatedDate) AS [ContactedDate], 
     'Email' AS [ContactMethod]  
FROM WorkingData.dbo.FactActivities FA 
WHERE FA.InboundEmail = 1 AND FA.CreatedDate >= CAST('12-04-2015' as date) 
GROUP BY FA.ContactID, 
     FA.Employee 
HAVING 
    (SELECT Count(*) 
    FROM WorkingData.dbo.FactActivities FA t2 
    WHERE t2.PrincipalCall = 1 AND FA.CreatedDate >= CAST('12-04-2015' as date) 
    AND t2.ContactID = FA.ContactID 
    AND t2.Employee = FA.Employee) = 0