sql从一个历史中获取新增客户和离开跟踪的客户table

Question

我有一个 Staff_Table 包含历史数据。每天都会添加新日期的相同员工名单（每天 1200-12500 名员工，但只有少数员工可能会在今天日期新添加，或者员工可能昨天离开公司并且没有出现在今天的名单上）。

我想知道每天哪些员工不在昨天的名单上（这是新员工，昨天出现但今天没有出现，因为他们离开了公司）。我已经尝试了以下但没有快乐请帮助我的历史 table 如下所示，我需要一个脚本来仅获取 ID4 和 ID5 的行。

StaffID StaffName CensusDate    
ID1     Staff1  02/03/2021  
ID1     Staff1  03/03/2021  
ID2     Staff2  02/03/2021  
ID2     Staff2  03/03/2021  
ID3     Staff3  02/03/2021  
ID3     Staff3  03/03/2021  
ID4     Staff4  02/03/2021  left-not showing today
ID5     Staff5  03/03/2021  New staff-is newly added today
ID6     Staff6  02/03/2021  
ID6     Staff6  03/03/2021  
ID7     Staff7  02/03/2021  
ID7     Staff7  03/03/2021

StaffID 为浮点型，id 可能只是 ID123，或 ID123-2 我有以下脚本，但我得到 'error converting data type nvarchar to float'

WITH CTE_TodaysStaff AS
(
    SELECT DISTINCT T1.StaffID
    FROM Staff_table AS T1
    WHERE T1.CensusDate = CAST(GETDATE() AS DATE)
),
CTE_NotShowingToday AS
(
    SELECT DISTINCT T1.StaffID
    FROM Staff_Table AS T1
    LEFT JOIN CTE_TodaysStaff AS T2
         ON T1.StaffID = T2.StaffID
    WHERE T1.CensusDate = CAST(DATEADD(DAY, -1, GETDATE()) AS DATE)
        AND T2.StaffID IS NULL
 ),
CTE_NewToday AS
(
    SELECT DISTINCT T1.StaffID
    FROM CTE_TodaysStaff AS T1
    LEFT JOIN Staff_table1 AS T2
        ON T1.StaffID = T2.StaffID
        AND T2.CensusDate < CAST(GETDATE() AS DATE)
    WHERE T2.StaffID IS NULL
 )

 SELECT T1.StaffID, T1.StaffNAME, T1.CensusDate, 
     CAST(CASE WHEN T2.StaffID IS NULL THEN 0 ELSE 1 END AS BIT) AS IsNotShowingToday,
     CAST(CASE WHEN T3.StaffID IS NULL THEN 0 ELSE 1 END AS BIT) AS IsNewToday
FROM Staff_table1 AS T1
LEFT JOIN CTE_NotShowingToday AS T2
    ON T1.StaffID = T2.StaffID
LEFT JOIN CTE_NewToday AS T3
    ON T1.StaffID = T3.StaffID

感谢任何帮助，谢谢

Answer 1

I want to know each day which staff wasn't on yesterday list(it is new staff and the staff was showing yesterday but not today because they left company)

您可以使用聚合：

select staffid,
       max(censusdate),
       (case when max(censusdate) = cast(getdate() as date) then 'New' else 'Removed' end) as which
from staff_table st
where censusdate >= dateadd(day, -1, cast(getdate() as date))
group by staffid
having count(*) = 1

这是什么逻辑？这只选择最近两天的数据。然后它按 staffid 聚合并仅选择在一个日期出现的那些。

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