排除別名欄中的'Null'

希望你們能幫助我。我是一名實習分析師，所以需要幫助。請看下面的查詢：排除別名欄中的'Null'

SELECT [PATHWAY_ID], [PAS_ID], [Patient_Name], [Pathway_Specialty], [Clinician], 
     [Referral_priority], [RTT_START_DTTM], [Days Waiting], [Activity Type], 
     [Last Activity Type], [Next_Appt_DTTM], [First_Appointment_Flag], 
     CASE WHEN [Days Waiting] <=97 AND [Next_Appt_DTTM] IS NOT NULL THEN 'Booked' 
      WHEN [Days Waiting] >=98 AND [Next_Appt_DTTM] IS NULL THEN 'Unbooked' 
     END AS 'Booked Status' 
FROM [GWH_RTT].[rtt].[GWH_RTT_Nonadmitted_PTL] 
WHERE [Referral_priority] = 'Routine' 
ORDER BY 'Booked Status' DESC

在我的別名列中，我有空的那裏，不匹配我的case語句。我如何讓SQL返回我的case語句，排除我的別名列中的空值？

來源

2016-06-28 Ang

這是一個CASE表達式（它返回一個值）。 case語句只是條件執行的代碼（例如在存儲過程中）。 – jarlh

謝謝，沒有意識到:) – Ang

如何使用子查詢或CTE：

with q as (<your query here without the order by>) 
select q.* 
from q 
where [Booked Status] is not null 
order by [Booked Status];

一句忠告：不要使用列別名單引號。僅對日期和字符串常量使用單引號。您可以在SQL Server中使用方括號或雙引號。

來源

2016-06-28 12:31:20

試試這個：

SELECT t.* 
FROM (SELECT [PATHWAY_ID], [PAS_ID], [Patient_Name], [Pathway_Specialty], [Clinician], 
     [Referral_priority], [RTT_START_DTTM], [Days Waiting], [Activity Type], 
     [Last Activity Type], [Next_Appt_DTTM], [First_Appointment_Flag], 
     CASE WHEN [Days Waiting] <=97 AND [Next_Appt_DTTM] IS NOT NULL THEN 'Booked' 
      WHEN [Days Waiting] >=98 AND [Next_Appt_DTTM] IS NULL THEN 'Unbooked' 
     END AS 'Booked Status' 
FROM [GWH_RTT].[rtt].[GWH_RTT_Nonadmitted_PTL] 
WHERE [Referral_priority] = 'Routine' 
) t 
WHERE t.[Booked Status] IS NOT NULL 
ORDER BY [Booked Status] DESC

來源

2016-06-28 12:34:16

排除別名欄中的'Null'

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