SQL Clone
SQLServerCentral is supported by Redgate
 
Log in  ::  Register  ::  Not logged in
 
 
 


Reporting in records in the right order


Reporting in records in the right order

Author
Message
aaron.reese
aaron.reese
SSCrazy
SSCrazy (2.4K reputation)SSCrazy (2.4K reputation)SSCrazy (2.4K reputation)SSCrazy (2.4K reputation)SSCrazy (2.4K reputation)SSCrazy (2.4K reputation)SSCrazy (2.4K reputation)SSCrazy (2.4K reputation)

Group: General Forum Members
Points: 2415 Visits: 907
hi guys

I have some data from a system upgrade where stuff didn't get the right sequence numbers

create #test
(
ref int,
oldvalue nvarchar,
newvalue nvarchar,
seqno int
)


insert into #test (ref,oldvalue,newvalue,seqno) values (100,null,'A',1)
insert into #test (ref,oldvalue,newvalue,seqno) values (100,'B','C',2)
insert into #test (ref,oldvalue,newvalue,seqno) values (100,'A','B',3)
insert into #test (ref,oldvalue,newvalue,seqno) values (100,'B','X',4)
insert into #test (ref,oldvalue,newvalue,seqno) values (100,'C','B',5)





the correct order for these records is actually 1,3,2,5,4 (oldvalue = newvalue from previous record). The challenge is that from seqno 3 you have two potential choices (2 or 4) but only the combination above collects all of the records.

I can't see how to do this without resorting to cursors or other RBAR solutions. any help would be appreciated. The dataset is approximately 900K records spread over 250K ref#s
Lowell
Lowell
SSC Guru
SSC Guru (71K reputation)SSC Guru (71K reputation)SSC Guru (71K reputation)SSC Guru (71K reputation)SSC Guru (71K reputation)SSC Guru (71K reputation)SSC Guru (71K reputation)SSC Guru (71K reputation)

Group: General Forum Members
Points: 71412 Visits: 40930
aaron i'm sure you know that SQL doesn't order data in any specific order without an explicit ORDER BY clause.

in your case, i'm thinking you might do what you want with a CASE statement, but i'm a little unclear on how the records actually match;
here's my first guess:

SELECT t1.*
FROM #test t1
LEFT OUTER JOIN #test t2
ON t1.ref = t2.ref
and t1.oldvalue = t2.newvalue
ORDER BY
t1.ref,
CASE WHEN t1.oldvalue is NULL THEN 1
WHEN t1.oldvalue = t2.newvalue then 2
else 3
end,
seqno



Lowell
--help us help you! If you post a question, make sure you include a CREATE TABLE... statement and INSERT INTO... statement into that table to give the volunteers here representative data. with your description of the problem, we can provide a tested, verifiable solution to your question! asking the question the right way gets you a tested answer the fastest way possible!
aaron.reese
aaron.reese
SSCrazy
SSCrazy (2.4K reputation)SSCrazy (2.4K reputation)SSCrazy (2.4K reputation)SSCrazy (2.4K reputation)SSCrazy (2.4K reputation)SSCrazy (2.4K reputation)SSCrazy (2.4K reputation)SSCrazy (2.4K reputation)

Group: General Forum Members
Points: 2415 Visits: 907
@Lowell,

Thats the challenge, when you use LEFT OUTER JOIN, seq#3 will join to both seq#2 and seq#4

In theory you have to traverse the entire tree to find out whether you can include all records. in a particular path. Short of using cursors to move records from a processed to an unprocessed state I can't see a simple method that will scale. It's not so much the SQL that I am struggling with as the actual programming concept. If I could get the stragegy I can probably write the SQL
Jeff Moden
Jeff Moden
SSC Guru
SSC Guru (214K reputation)SSC Guru (214K reputation)SSC Guru (214K reputation)SSC Guru (214K reputation)SSC Guru (214K reputation)SSC Guru (214K reputation)SSC Guru (214K reputation)SSC Guru (214K reputation)

Group: General Forum Members
Points: 214208 Visits: 41979
[Edit] Sorry, misread the original problem so withdrew my comment. Not yet sure with how to resolve the "fork in the road". Reminds me of "Yogi". "When you come to a fork in the road, take it!". :-P

--Jeff Moden

RBAR is pronounced ree-bar and is a Modenism for Row-By-Agonizing-Row.
First step towards the paradigm shift of writing Set Based code:
Stop thinking about what you want to do to a row... think, instead, of what you want to do to a column.
If you think its expensive to hire a professional to do the job, wait until you hire an amateur. -- Red Adair

Helpful Links:
How to post code problems
How to post performance problems
Forum FAQs
mister.magoo
mister.magoo
SSChampion
SSChampion (10K reputation)SSChampion (10K reputation)SSChampion (10K reputation)SSChampion (10K reputation)SSChampion (10K reputation)SSChampion (10K reputation)SSChampion (10K reputation)SSChampion (10K reputation)

Group: General Forum Members
Points: 10573 Visits: 7891
Will there always be a path that includes all rows for a particular Ref#?

MM


select geometry::STGeomFromWKB(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




  • Forum Etiquette: How to post Reporting Services problems
  • Forum Etiquette: How to post data/code on a forum to get the best help - by Jeff Moden
  • How to Post Performance Problems - by Gail Shaw

  • Go


    Permissions

    You can't post new topics.
    You can't post topic replies.
    You can't post new polls.
    You can't post replies to polls.
    You can't edit your own topics.
    You can't delete your own topics.
    You can't edit other topics.
    You can't delete other topics.
    You can't edit your own posts.
    You can't edit other posts.
    You can't delete your own posts.
    You can't delete other posts.
    You can't post events.
    You can't edit your own events.
    You can't edit other events.
    You can't delete your own events.
    You can't delete other events.
    You can't send private messages.
    You can't send emails.
    You can read topics.
    You can't vote in polls.
    You can't upload attachments.
    You can download attachments.
    You can't post HTML code.
    You can't edit HTML code.
    You can't post IFCode.
    You can't post JavaScript.
    You can post emoticons.
    You can't post or upload images.

    Select a forum

































































































































































    SQLServerCentral


    Search