Question

此查询

      SELECT PA.refPatient_id
            ,MAX(PA.datee) AS datee
            ,PR.temporary,PA.statue

        FROM PatientClinicActs AS PA
            ,PatientStatueReasons AS PR

       WHERE PA.refClinic_id = 25 
         AND PA.refreason_id = PR.reason_id

    GROUP BY PA.refPatient_id,PA.statue,PR.temporary

返回以下结果：

refPatient_id datee                 temporary statue
----------- ----------------------- ------ -----
14706       2008-12-01 11:01:00     1      0
14707       2009-05-18 16:21:00     1      0
14708       2009-07-15 09:46:00     1      0
14708       2009-07-29 16:12:00     1      0
14716       2009-11-09 12:29:00     0      0
14716       2009-09-01 11:15:00     1      0
14716       2009-09-29 16:44:00     1      1

但我希望得到这些结果：

refPatient_id datee                   temporary statue
----------- ----------------------- ------ -----
14706       2008-12-01 11:01:00     1      0
14707       2009-05-18 16:21:00     1      0
14708       2009-07-29 16:12:00     1      0
14716       2009-11-09 12:29:00     0      0

有什么区别？ =＆GT;我在这些结果中为每个refPatient_id提供了最新的行。我该怎么办才能得到这些结果？

Answer 1

尝试这样的事情

SELECT  PA.refPatient_id,
        PA.datee,
        PR.temporary,
        PA.statue
FROM    PatientClinicActs AS PA INNER JOIN
        (
            SELECT  PA.refPatient_id,
                    MAX(PA.datee) AS datee
            FROM    PatientClinicActs AS PA
            WHERE   PA.refClinic_id = 25          
            GROUP BY PA.refPatient_id,PA.statue,PA.datee,
        ) AS MaxDates ON PA.refPatient_id = MaxDates.refPatient_id AND PA.datee = MaxDates.datee INNER JOIN
        PatientStatueReasons AS PR ON PA.refreason_id = PR.reason_id

您需要先获得每位患者的最长日期，然后加入。

Answer 2

而不是交叉连接

FROM PatientClinicActs AS PA
                ,PatientStatueReasons AS PR

你可以试试内连接

FROM PatientClinicActs AS PA

INNER JOIN PatientStatueReasons AS PR 

ON PA.refreason_id = PR.reason_id

WHERE PA.refClinic_id = 25

Answer 3

对于这种情况，还有另一种方法可以使用SQL Server Ranking functions来获取最新的记录。

我已使用DENSE_RANK()作为答案，但您可以使用RANK()代替您的特定问题。
（注意：以下代码未经过测试。如果您要为表提供架构，我会测试样本数据）

;with RankedResult as (
    SELECT  
    PA.refPatient_id
    , PA.datee
    , PR.temporary,
    , PA.statue
    --; Last datee has the lowest rank value of 1,
    , dense_rank() over 
        (partition by PA.refPatient_id order by PA.datee desc) as [Rank]
    FROM    PatientClinicActs AS PA
            join PatientStatueReasons AS PR on PA.refreason_id = PR.reason_id
    WHERE   PA.refClinic_id = 25 
)
select  distinct *
from    RankedResult
--; Get only the last result.
where   [Rank] = 1

Answer 4

将PA.datee从group by子句

中取出

T-Sql，如何获得这些结果？

4 个答案: