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Sql question

Posted on 2014-12-18
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Last Modified: 2014-12-18
Hi Experts,

I have a table containing:

ID
PatientID
DateStarted
Subject

How do I get the ID of the latest day per patient, per subject?
I would prefer to have this in one query/view.
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Question by:bfuchs
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7 Comments
 
LVL 22

Expert Comment

by:Flyster
ID: 40508406
Try this:

SELECT tblYourTable.[PatientID], Last(tblYourTable.[DateStarted]) AS LastOfDateStarted, Last(tblYourTable.[Subject]) AS LastOfSubject
FROM tblYourTable
GROUP BY tblYourTable.[PatientID];

Open in new window


Flyster
0
 
LVL 120

Expert Comment

by:Rey Obrero (Capricorn1)
ID: 40508432
try this query


SELECT A.*
 FROM TableX AS A
 INNER JOIN
 (SELECT PatientID, Max([DateStarted]) AS MaxOfDate, Subject
      FROM TableX  GROUP BY PatientID, Subject)  AS B
      ON A.[DateStarted]=B.MaxOfDate AND A.PatientID=B.PatientID AND A.Subject=B.Subject
0
 
LVL 4

Author Comment

by:bfuchs
ID: 40508484
@Ray,
It works great,
Just one question, if I want to exclude a subject where do I put it?

@Flyster,
I cant see how your example would work in my case, I need the ID of the record containing the highest date of patient per subject.

Thanks,
Ben
0
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LVL 22

Expert Comment

by:Flyster
ID: 40508496
Sorry, missed that part. How about this:
SELECT Last(tblYourTable.ID) AS LastOfID, tblYourTable.PatientID, Last(tblYourTable.DateStarted) AS LastOfDateStarted, Last(tblYourTable.Subject) AS LastOfSubject
FROM tblYourTable
GROUP BY tblYourTable.PatientID

Open in new window


To exclude a particular subject, see the last line:
SELECT Last(tblYourTable.ID) AS LastOfID, tblYourTable.PatientID, Last(tblYourTable.DateStarted) AS LastOfDateStarted, Last(tblYourTable.Subject) AS LastOfSubject
FROM tblYourTable
GROUP BY tblYourTable.PatientID
HAVING (((Last(tblYourTable.Subject))<>"Enter_Your_Subject_Here"));

Open in new window

0
 
LVL 4

Author Comment

by:bfuchs
ID: 40508506
@Flyster,

Last(tblYourTable.ID) AS LastOfID..Group by PatientID would give me the highest ID per patient, not necessary the ID that belongs to the records containing the highest date.

Re excluding one subject, can you tell me how to modify Ray's suggestion to include this portion?

Thanks,
Ben
0
 
LVL 120

Accepted Solution

by:
Rey Obrero (Capricorn1) earned 2000 total points
ID: 40508507
change "What Subject" with the subject you want to exclude


SELECT A.*
 FROM TableX AS A
 INNER JOIN
 (SELECT PatientID, Max([DateStarted]) AS MaxOfDate, Subject
      FROM TableX  
      Where Subject <> "What Subject"
      GROUP BY PatientID, Subject)  AS B
      ON A.[DateStarted]=B.MaxOfDate AND A.PatientID=B.PatientID AND A.Subject=B.Subject
0
 
LVL 4

Author Closing Comment

by:bfuchs
ID: 40508562
Excellent, Thank You!
0

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