Question

我尝试通过 SQL或Access 进行查询以跟踪患者的动作，但真的很挣扎。我面临的问题是，每位患者每天只有一个位置，但患者可以在病房之间往返，因此尝试使用患者/位置并且最大和最小日期是不够的。

示例：

 - RowID: 1 Patient A - Ward 10 - 01/01/2015  
 - RowID: 2 Patient A - Ward 10 - 02/01/2015
 - RowID: 3 Patient A - Ward 11 - 03/01/2015  
 - RowID: 4 Patient A - Ward 10 - 04/01/2015
 - RowID: 5 Patient B - Ward 11 - 01/01/2015

正如您所看到的，每天只会捕获一次该位置，但我想开发一个动作，如果max date grouped by patient and ward将使用我的- Patient A - Ward 10 01/01/2015 - 02/01/2015 - Patient A - Ward 11 03/01/2015 - 03/01/2015 - Patient A - Ward 10 04/01/2015 - - Patient B - Ward 11 01/01/2015 -将在04的Ward 10上给出最后一个日期/ 01/2015，这在技术上是正确的，但我想在02/01/2015捕获运动。我希望能够显示以下内容：

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非常感谢任何帮助

亲切的问候， SIE

Answer 1

您需要使用相同的表格设置Self Join并使用条件对齐行，以便它们彼此相邻排列

设定：

SELECT * INTO #TABLE FROM 
(
SELECT 1 ROWID, 'Patient A' PAT , 'Ward 10' loc ,'01/01/2015' recorddate UNION ALL
select 2 ROWID, 'Patient A' PAT , 'Ward 10' loc ,'02/01/2015' recorddate UNION ALL
select 3 ROWID, 'Patient A' PAT , 'Ward 11' loc ,'03/01/2015' recorddate  UNION ALL
select 4 ROWID, 'Patient A' PAT , 'Ward 10' loc ,'04/01/2015' recorddate UNION ALL
select 5 ROWID, 'Patient B' PAT , 'Ward 11' loc ,'01/01/2015' recorddate) A

查询：

SELECT 
A.pat, A.loc, a.recorddate, MIN(b.recorddate) 
FROM #table A
INNER JOIN #TABLE B
ON A.PAT=B.pat
and (A.recorddate<B.recorddate)
group by A.ROWID, A.pat, A.loc, a.recorddate

UNION ALL 
-- Get the row that donot have a To Date

SELECT A.PAT, LOC , A.recorddate, NULL
FROM #table A
INNER JOIN (SELECT 
B.pat, MAX(B.recorddate) recorddate
FROM #table B
GROUP BY B.PAT) B
on A.PAT=B.PAT
and A.recorddate=B.recorddate

结果：

pat         loc     FROMDATE    TODATE
Patient A   Ward 10 01/01/2015  02/01/2015
Patient A   Ward 10 02/01/2015  03/01/2015
Patient A   Ward 11 03/01/2015  04/01/2015
Patient B   Ward 11 01/01/2015  NULL
Patient A   Ward 10 04/01/2015  NULL

每个条件只有一个日期时的访问/ SQL查询

1 个答案: