grouping without aggregates

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grouping without aggregates

Christopher Klein

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Points: 2648
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May 29, 2007 at 9:03 am

#176864

Hello,
I have a table of dates, accounts and values. I am trying to get the earliest occurance of each account and its value.
data:
12/31/2002,PARENT,'RECORDCODE1',ACCT1,10000
01/31/2003,PARENT,'RECORDCODE1',ACCT1,12000
02/28/2003,PARENT,'RECORDCODE1',ACCT1,13000
03/30/2003,PARENT,'RECORDCODE1',ACCT1,14000
04/30/2003,PARENT,'RECORDCODE1',ACCT1,15000
05/30/2003,PARENT,'RECORDCODE1',ACCT1,10000
07/30/2005,PARENT,'RECORDCODE2',ACCT2,10000
08/31/2005,PARENT,'RECORDCODE2',ACCT2,12000
09/28/2005,PARENT,'RECORDCODE2',ACCT2,13000
10/30/2005,PARENT,'RECORDCODE2',ACCT2,14000
10/30/2005,PARENT,'RECORDCODE2',ACCT2,15000
11/30/2005,PARENT,'RECORDCODE2',ACCT2,10000
etc,etc...
So I just cant seem to figure out how to get the 12/31/2002, ACCT1 record and the 07/30/2005, ACCT2 record.
So there are 10517 total records in the system. If I use this query:
SELECT MIN(DATE)
,PARENT
,RECORDCODE
,MIN(QUANTITY)
FROM TABLE
GROUP BY RECORDCODE,PARENT --,QUANTITY
ORDER BY DATE,RECORDCODE
I am able to get the 406 unique occurances of the EARLIEST dates. The problem is that I have to select the aggregate QUANTITY which skews the numbers. If I want to get the real number I have to remove the MIN() but then I get all 10k records.
What am I missing on this?!?
thanks,
Chris

Viewing 9 posts - 1 through 8 (of 8 total)

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ChrisM@Work SSC Guru Points: 186127 More actions · Answer 1

Hi Chris

This should do the trick.

CREATE TABLE #MSG369550 (AccountDate DATETIME, parent CHAR(6), RecordCode CHAR(11), AccountName CHAR(5), Quantity INT)

INSERT INTO #MSG369550 VALUES ('12/31/2002','PARENT','RECORDCODE1','ACCT1',10000)

INSERT INTO #MSG369550 VALUES ('01/31/2003','PARENT','RECORDCODE1','ACCT1',12000)

INSERT INTO #MSG369550 VALUES ('02/28/2003','PARENT','RECORDCODE1','ACCT1',13000)

INSERT INTO #MSG369550 VALUES ('03/30/2003','PARENT','RECORDCODE1','ACCT1',14000)

INSERT INTO #MSG369550 VALUES ('04/30/2003','PARENT','RECORDCODE1','ACCT1',15000)

INSERT INTO #MSG369550 VALUES ('05/30/2003','PARENT','RECORDCODE1','ACCT1',10000)

INSERT INTO #MSG369550 VALUES ('07/30/2005','PARENT','RECORDCODE2','ACCT2',10000)

INSERT INTO #MSG369550 VALUES ('08/31/2005','PARENT','RECORDCODE2','ACCT2',12000)

INSERT INTO #MSG369550 VALUES ('09/28/2005','PARENT','RECORDCODE2','ACCT2',13000)

INSERT INTO #MSG369550 VALUES ('10/30/2005','PARENT','RECORDCODE2','ACCT2',14000)

INSERT INTO #MSG369550 VALUES ('10/30/2005','PARENT','RECORDCODE2','ACCT2',15000)

INSERT INTO #MSG369550 VALUES ('11/30/2005','PARENT','RECORDCODE2','ACCT2',10000)

SELECT a.*

FROM #MSG369550 a

INNER JOIN (

SELECT MIN(AccountDate) AS MinAccountDate, AccountName

FROM #MSG369550

GROUP BY AccountName) d

ON d.AccountName = a.AccountName and d.MinAccountDate = a.AccountDate

DROP TABLE #MSG369550

Cheers

ChrisM

^{“Write the query the simplest way. If through testing it becomes clear that the performance is inadequate, consider alternative query forms.” - Gail Shaw}

For fast, accurate and documented assistance in answering your questions, please read this article.
Understanding and using APPLY, (I) and (II) Paul White
Hidden RBAR: Triangular Joins / The "Numbers" or "Tally" Table: What it is and how it replaces a loop Jeff Moden

Christopher Klein SSCrazy Points: 2648 More actions · Answer 2

Chris,

Well, your solution was certainly more efficient than mine using

SELECT Row_NUMBER() OVER (Partition BY CUSIP ORDER BY EOM_DATE) AS OrderRank

stuffing the results into a @temp and then selecting the items where OrderRank=1

I defintally like your solution. What bugs me is that I knew that I could probably do it with a derived table/join and just couldnt figure the darn thing.

thanks,

Chris

Michael Earl-395764 SSC Guru Points: 53873 More actions · Answer 3

Just watch out for performance on this one.

To process the join to itself by date, SQL is going to probably use a cursor internally and this may cause you some performance issues if your table gets large enough.

There are lots of ways to do this - and the one posted is a pretty good way - just check your execution plan and performance to make sure this will work for your data set.

Sue Stengel SSC Rookie Points: 47 More actions · Answer 4

here's another way using a correlated subquery in the where clause

(see Chris's post above for the table structure and data)

select * from #MSG369550 a

where accountdate = (select min(accountdate) from #MSG369550

where a.accountname = accountname)

Jeff Moden SSC Guru Points: 1004248 More actions · Answer 5

Chris,

Turn that SELECT into a CTE instead of using a table variable...

--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.

Change is inevitable... Change for the better is not.

Helpful Links:
How to post code problems
How to Post Performance Problems
Create a Tally Function (fnTally)

ChrisM@Work SSC Guru Points: 186127 More actions · Answer 6

Hi Jeff

We're on SQL2k here. Can't wait to play with CTE on the next contract though.

Regarding matching on dates - good point. If an identity column is available, the same query would require very little amendment to join on id column instead of date.

Cheers

ChrisM

^{“Write the query the simplest way. If through testing it becomes clear that the performance is inadequate, consider alternative query forms.” - Gail Shaw}

For fast, accurate and documented assistance in answering your questions, please read this article.
Understanding and using APPLY, (I) and (II) Paul White
Hidden RBAR: Triangular Joins / The "Numbers" or "Tally" Table: What it is and how it replaces a loop Jeff Moden

Jeff Moden SSC Guru Points: 1004248 More actions · Answer 7

Ok, Chris... but the OP did post some SQL Server 2k5 code.

{Edit}... sorry misread that... YOU have SQL Server 2k... I get it...

--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.

Change is inevitable... Change for the better is not.

Helpful Links:
How to post code problems
How to Post Performance Problems
Create a Tally Function (fnTally)

Jeff Moden SSC Guru Points: 1004248 More actions · Answer 8

Not to worry... no internal cursor...

--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.

Change is inevitable... Change for the better is not.

Helpful Links:
How to post code problems
How to Post Performance Problems
Create a Tally Function (fnTally)