?
Solved

Delete unwanted rows

Posted on 2013-06-15
5
Medium Priority
?
242 Views
Last Modified: 2013-07-01
I have a table "TreatmentData" defined as:

create table #TreatmentData(
 
  PatientId nvarchar(18),
  TreatedWith nvarchar(30) );

The table lists patient treatments.  A patient can have many rows in the table.  There are six possible values for TreatedWith.

I need to delete all the patient records where the patient has "NoTreatment" for all his/her rows in the database.  i.e. they have visited the clinic but not been treated.

I imagine it must be where the number of rows is equal to the count where the TreatedWith is "NoTreatment" when grouped by PatientId...

but i just can not get my head round it.

Any suggestions?
0
Comment
Question by:soozh
5 Comments
 
LVL 16

Assisted Solution

by:Surendra Nath
Surendra Nath earned 1000 total points
ID: 39250522
the below query might help you out

;with CTE as
(
 select PatientId,TreatedWith  from #TreatmentData group by PatientId,TreatedWith 
), CTE1 AS
(
 select PatiendID from CTE C WHERE NOT EXISTS ( select 1 FROM CTE C1 where C1.PatiendID = C.PatiendID and C1.TreatedWith  <> 'NoTreatment')
)
DELETE T
FROM #TreatmentData T
JOIN CTE1 C
ON T.PatiendID = C.PatiendID

Open in new window

0
 
LVL 5

Expert Comment

by:DOSLover
ID: 39250869
Essentially what we are saying here is that delete the patient record if we find only 'NoTreatment' records for that patient:
Delete from TreatmentData a
 where exists 
       (Select PatientId from TreatmentData b
	     where b.PatientId = a.PatientId
		   and b.TreatedWith = 'NoTreatment')
   and NOT exists 
       (Select PatientId from TreatmentData b
	     where b.PatientId = a.PatientId
		   and b.TreatedWith <> 'NoTreatment')

Open in new window

0
 
LVL 32

Accepted Solution

by:
Ephraim Wangoya earned 1000 total points
ID: 39251119
Here

with cte as
(
  select *
  from TreatmentData
  where TreatedWith <> 'NoTreatment'
)

delete from TreatMentData
where not exists(select 1 
                           from cte A
                           where TreatmentData.PatientID = A.PatientID)

Open in new window

0
 
LVL 25

Expert Comment

by:chaau
ID: 39252003
Just kidding: when you apply all the SQL statements against you treatment table that you have asked during last week, you will probably end up with a nice empty table. Ha-ha
0
 
LVL 32

Expert Comment

by:awking00
ID: 39253464
delete from treatmentdata
where patientid in
(select patientid from treatmentdata where treatedwith = 'NoTreatment'
 except
 select patientid from treatmentdata where treatedwith <> 'NoTreatment')
0

Featured Post

Free Tool: SSL Checker

Scans your site and returns information about your SSL implementation and certificate. Helpful for debugging and validating your SSL configuration.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

An alternative to the "For XML" way of pivoting and concatenating result sets into strings, and an easy introduction to "common table expressions" (CTEs). Being someone who is always looking for alternatives to "work your data", I came across this …
This shares a stored procedure to retrieve permissions for a given user on the current database or across all databases on a server.
With just a little bit of  SQL and VBA, many doors open to cool things like synchronize a list box to display data relevant to other information on a form.  If you have never written code or looked at an SQL statement before, no problem! ...  give i…
Stellar Phoenix SQL Database Repair software easily fixes the suspect mode issue of SQL Server database. It is a simple process to bring the database from suspect mode to normal mode. Check out the video and fix the SQL database suspect mode problem.

592 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question