如何解决使用临时表的 SQL 查询会为所使用的每个 case 语句复制结果
我需要能够提取当前注册的学生，然后根据他们所属的第一个类别定义更小的子术语、状态和标签。类别-运动员，双学分，美术，健康专业，CTE，校园1，校园2，校园3，在线，校园4，无作业
我需要的大部分信息都在几个表中，并且主键在所有表中的标记都不同。我创建了三个临时表，一个用于学生，另外两个用于其余信息。然后我加入了所有三个表并使用 case 语句来查看我们想要使用的子术语和分组层次结构。
查询能够提取所有内容并且 case 语句起作用，问题是当它们属于多个类别时，它们的记录会重复。我尝试将 case 语句放在相关的临时表中，然后在所有三个表都连接但没有任何效果的最终查询中。
最初我使用 Tableau 并且能够做所有事情，但在查看一个或多个术语时出现了同样的问题，当学生属于多个类别时，计数会重复。
前学生正在参加一个 16 周的课程和两个 8 周的课程。她是一名美术学生，在 CTE 计划中，她将属于美术类别，并且每个子术语都有该标题。
Example 1 --> 独特的 ID 21/SP CTE
Example 2 --> 独特的 ID 21/SP 在线
这是最后使用的最终查询，它将三个表连接到#ENROLL 表上，其中原始临时表用于查询我们需要的学生并得到一个不同的列表。
SELECT disTINCT E.STUDENT_ID AS "S_ID",--#PROG.PROGRAM,#SPECIAL.[NEW/RETURNER],CASE
WHEN ENROLL_START_DATE = '01/19/2021' AND E.ENROLL_END_DATE = '05/11/2021' THEN '21/SP 16W'
WHEN [ENROLL_START_DATE] = '01/19/2021' AND ENROLL_END_DATE = '03/17/2021' THEN '21/SP 8W1'
WHEN [ENROLL_START_DATE] = '03/22/2021' AND ENROLL_END_DATE = '05/11/2021' THEN '21/SP 8W2'
WHEN [ENROLL_START_DATE] = '05/17/2021' AND ENROLL_END_DATE = '06/03/2021' THEN '21/SP MM'
WHEN [ENROLL_START_DATE] = '06/07/2021' AND ENROLL_END_DATE = '07/12/2021' THEN '21/S1 6W1'
WHEN [ENROLL_START_DATE] = '06/07/2021' AND ENROLL_END_DATE = '08/16/2021' THEN '21/S1 12W'
WHEN [ENROLL_START_DATE] = '07/13/2021' AND ENROLL_END_DATE = '08/16/2021' THEN '21/S2 6W2'
WHEN [ENROLL_START_DATE] = '08/23/2021' AND ENROLL_END_DATE = '12/11/2021' THEN '21/FA 16W'
WHEN [ENROLL_START_DATE] = '08/23/2021' AND ENROLL_END_DATE= '10/13/2021' THEN '21/FA 8W1'
WHEN [ENROLL_START_DATE] = '10/18/2021' AND ENROLL_END_DATE = '12/11/2021' THEN '21/FA 8W2'
--ELSE ' '
END AS [SUB TERM],CASE
WHEN #SPECIAL.GROUPING = 'ATHLETE' THEN 'ATHLETE'
WHEN DC.DC_RESTRICTION = 'CCHS' THEN 'DC'
WHEN #SPECIAL.GROUPING = 'FA' THEN 'FA'
WHEN #PROG.PROGRAM = 'HP' THEN 'HP'
WHEN #PROG.PROGRAM = 'CTE' THEN 'CTE'
WHEN #SPECIAL.GROUPING = 'MEX' THEN 'MEXIA CAmpuS'
WHEN #SPECIAL.GROUPING = 'WAX' THEN 'WAXAHACHIE CAmpuS'
WHEN #SPECIAL.GROUPING = 'MID' THEN 'MIDLOTHIAN CAmpuS'
WHEN #SPECIAL.GROUPING = 'ITN' THEN 'ONLINE'
WHEN #SPECIAL.GROUPING = 'CC' THEN 'CORSICANA CAmpuS'
ELSE ' '
END AS 'NEW GROUP'
FROM #ENROLL E
LEFT JOIN #SPECIAL ON #SPECIAL.N05_STTR_STUDENT = E.STUDENT_ID
LEFT JOIN #PROG ON #PROG.N05_PRGM_STUDENT = E.STUDENT_ID
LEFT JOIN [coll18_prod].[dbo].N05_DUAL_CREDIT DC ON DC_ID = E.STUDENT_ID
ORDER BY S_ID
更新： 我为每个学期的每个类别创建了一个排名。
IF OBJECT_ID('tempdb..#RANK') is not null
DROP TABLE #RANK
SELECT *,CASE
WHEN #ENROLL_1.[NEW GROUP] LIKE 'ATHLETE' THEN 1
WHEN #ENROLL_1.[NEW GROUP] LIKE 'DC' THEN 2
WHEN #ENROLL_1.[NEW GROUP] LIKE 'FA' THEN 3
WHEN #ENROLL_1.[NEW GROUP] LIKE 'HP' THEN 4
WHEN #ENROLL_1.[NEW GROUP] LIKE 'CTE' THEN 5
WHEN #ENROLL_1.[NEW GROUP] LIKE 'MEXIA CAmpuS' THEN 6
WHEN #ENROLL_1.[NEW GROUP] LIKE 'WAXAHACHIE CAmpuS' THEN 7
WHEN #ENROLL_1.[NEW GROUP] LIKE 'MIDLOTHIAN CAmpuS' THEN 8
WHEN #ENROLL_1.[NEW GROUP] LIKE 'ONLINE' THEN 9
WHEN #ENROLL_1.[NEW GROUP] LIKE 'CORSICANA CAmpuS' THEN 10
WHEN #ENROLL_1.[NEW GROUP] LIKE ' ' THEN 11
ELSE ' '
END AS [RANK],CASE
WHEN #ENROLL_1.[SUB TERM] LIKE '21/SP 16W' THEN '21/SP 16W'
WHEN #ENROLL_1.[SUB TERM] LIKE '21/SP 8W1' THEN '21/SP 8W1'
WHEN #ENROLL_1.[SUB TERM] LIKE '21/SP 8W2' THEN '21/SP 8W2'
WHEN #ENROLL_1.[SUB TERM] LIKE '21/SP MM' THEN '21/SP MM'
WHEN #ENROLL_1.[SUB TERM] LIKE '21/S1 6W1' THEN '21/S1 6W1'
WHEN #ENROLL_1.[SUB TERM] LIKE '21/S1 12W' THEN '21/S1 12W'
WHEN #ENROLL_1.[SUB TERM] LIKE '21/S2 6W2' THEN '21/S2 6W2'
WHEN #ENROLL_1.[SUB TERM] LIKE '21/FA 16W' THEN '21/FA 16W'
WHEN #ENROLL_1.[SUB TERM] LIKE '21/FA 8W1' THEN '21/FA 8W1'
WHEN #ENROLL_1.[SUB TERM] LIKE '21/FA 8W2' THEN '21/FA 8W2'
ELSE ' '
END AS [S_TERM]
INTO #RANK
FROM #ENROLL_1
SELECT disTINCT #RANK.S_ID,#RANK.[NEW/RETURNER],#RANK.S_TERM,#RANK.[NEW GROUP],MIN(#RANK.[RANK]) FROM #RANK
WHERE #RANK.S_ID = '0011339'
AND #RANK.[NEW GROUP] <> ' '
GROUP BY #RANK.S_ID,#RANK.[RANK]
ORDER BY S_ID
结果很接近，但它提取了多个值。例子在图片中 enter image description here
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