如何在SQL Server中使用SQL实现以下任务

Question

我完成了这个任务，我必须从care_team_member_name表中选择DIM_CARE_TEAM_MEMBER。条件是对于特定的care_team_member_Engagement_id，我们需要选择活跃的成员，即其care_team_member_end_date为null，对于非活动成员，我们选择该特定care_team_member_end_date的最大care_team_member_Engagement_id。

我能够使用以下查询实现第二部分

select  
    [care_team_member_name], 
    [care_team_member_Engagement_id],
    [care_team_member_end_date],
    B.A 
from 
    (select 
         care_team_member_name,care_team_member_end_date,
         [care_team_member_Engagement_id],
         row_number() over(partition by [care_team_member_Engagement_id] order by care_team_member_end_date) A
     from 
         DIM_CARE_TEAM_MEMBER) B  
where 
    B.A = 1

但我无法实现我选择care_team_member_name作为特定参与ID的第一部分

例如：

care_team_member_name   care_team_member_Engagement_id  care_team_member_start_date care_team_member_end_date
TM-000022181            a1Y0q0000000woaEAA               2017-08-16                  NULL
TM-000022182            a1Y0q0000000wobEAA               2017-08-16                  NULL
TM-000022183            a1Y0q0000000wocEAA               2017-08-16                  NULL
TM-000022184            a1Y0q0000000wodEAA               2017-08-16                  NULL
TM-000022185            a1Y0q0000000woeEAA               2017-08-16                  NULL
TM-000030523            a1Y0q0000000woVEAQ               2018-01-03                  2018-02-28
TM-000031508            a1Y0q0000000woVEAQ               2018-01-25                  2018-02-28
TM-000031798            a1Y0q0000000woVEAQ               2018-03-01                  2018-03-05
TM-000031802            a1Y0q0000000woVEAQ               2018-03-01                  2018-03-05
TM-000031803            a1Y0q0000000woVEAQ               2018-03-01                  2018-03-05
TM-000031805            a1Y0q0000000woVEAQ               2018-03-01                  2018-03-05
TM-000031806            a1Y0q0000000woVEAQ               2018-03-01                  2018-03-05
TM-000023500            a1Y0q0000000woVEAQ               2017-09-21                  2018-03-05
TM-000023503            a1Y0q0000000woVEAQ               2017-09-22                  2018-03-05

从这个表中，我必须选择结束日期为null的名称

Answer 1

我不确定我是否正确理解了这个问题，但试试这个：

SELECT tm.*
FROM (
    SELECT care_team_member_Engagement_id id, 
         NULLIF(MAX(coalesce(care_team_member_end_date,'29991231')),'29991231') end_date 
    FROM DIM_CARE_TEAM_MEMBER
    GROUP BY care_team_member_Engagement_id 
) ids
INNER JOIN DIM_CARE_TEAM_MEMBER tm ON
        tm.care_team_member_Engagement_id = ids.id 
    AND tm.care_team_member_end_date = ids.end_date