Solved

Need help writing a query

Posted on 2015-01-13
4
57 Views
Last Modified: 2015-01-17
Experts,

Details have been attached

Thanks in advance.
ItemDetails.docx
0
Comment
Question by:Tpaul_10
  • 2
  • 2
4 Comments
 
LVL 18

Accepted Solution

by:
Simon earned 500 total points
ID: 40547980
To clarify:
need to get the list of distinct ItemIDs where an Item has an ItemCode stating with “G” and it’s previous ItemCode starting with “C”
You write HAS an itemCode starting wtih 'G' (implying that this is the CURRENT status), but, you expect to see ID2 in your results even though that doesn't have a current itemCode starting with G. It does have two sequential historic records with ItemCodes GP and CF (with historicIDs 3 and 2 respectively).

Can I just confirm that the chronological order of the ItemHistoryID values runs 1,2,3,4,5,n..0, where 1 is the oldest status, 2 is the next oldest status and n is the most recently superseded status?

Your item ID3 has 3 rows, all with ItemHistoryID =0. How can the same item have 3 different 'latest/current' statuses?
        ('IP3', 0, 'GP'),
      ('IP3', 0, 'N'),
      ('IP3', 0, 'CF'),
      ('IP3', 1, 'IP')

** In listings below, replace t1 with the name of your table  **

This code gets you CURRENT itemCode like G% with immediate predecessor like C%
with cteCurr as (
  select ItemID,ItemHistoryID,ItemCode from t1 where ItemHistoryID=0),
cteHist as (
   select ItemID,ItemHistoryID,ItemCode
  ,row_number() over (partition by itemID order by ItemHistoryID desc) as HistRank 
  from t1 where ItemHistoryID>0)

select cteCurr.ItemID,cteCurr.ItemCode as CurrCode,cteHist.itemCode as LastCode 
from cteCurr inner join ctehist on ctecurr.itemID=ctehist.itemID
where cteCurr.itemcode like 'G%' and cteHist.Itemcode like 'C%' and cteHist.HistRank = 1

Open in new window


This code gets you ANY itemCode  like G% with immediate predecessor like C%
with cteCurr as (
  select ItemID,ItemHistoryID,ItemCode,0 as HistRank from t1 where ItemHistoryID=0),
cteHist as (
   select ItemID,ItemHistoryID,ItemCode
  ,row_number() over (partition by itemID order by ItemHistoryID desc) as HistRank 
  from t1 where ItemHistoryID>0),
cteAll as (select * from cteCurr UNION ALL select * from cteHist)

select c.ItemID,c.ItemCode as CurrCode,p.itemCode as LastCode 
from cteAll c inner join cteAll p on c.itemID=p.itemID and p.histrank=c.histrank+1
where c.itemcode like 'G%' and p.Itemcode like 'C%' 

Open in new window


This is the test table for the above listings:
CREATE TABLE T1
	([ItemId] varchar(3), [ItemHistoryID] int, [ItemCode] varchar(2))
;
	
INSERT INTO T1
	([ItemId], [ItemHistoryID], [ItemCode])
VALUES
	('IP1', 0, 'GN'),
	('IP1', 1, 'N'),
	('IP1', 2, 'CF'),
	('IP2', 0, 'GN'),
	('IP2', 1, 'N'),
	('IP2', 2, 'CF'),
	('IP2', 3, 'GP'),
	('IP3', 0, 'GP'),
	('IP3', 0, 'N'),
	('IP3', 0, 'CF'),
	('IP3', 1, 'IP')
;

Open in new window

0
 

Author Comment

by:Tpaul_10
ID: 40548039
Thanks for the quick reply Simon and appreciate your questions. Here are the details and please excuse me for the confusion.

1. Not considering the historyID, I need to find out the items having itemcode starting with "C%" with the next row/transaction starting with  "G%".  (That was the reason I have had IP2 in my output.)
2. Yes, 1 is the oldest and 0 is the latest
3. on IP3 it should 0,1,2,3 and it was a type from me.

I have tried the above code and not returning rows but I will verify it again and hope I have clarified what I am looking for in #1

Thanks again.
0
 
LVL 18

Expert Comment

by:Simon
ID: 40549318
Hi,

>"Not considering the historyID"
It seems you do need to consider (make use of) the ItemHistoryID column to order the data. If you don't order the data by ItemID then ItemHistoryID, there is no way of determining which the 'next row/transaction' will be.

Here's some revised code in a self-contained block, with the test data table included to make it easy to check the results.
declare @t1  table (ItemID  char(3),ItemHistoryID  int,ItemCode  varchar(5))

insert into @t1 values
('IP1',	0,	'GN'),
('IP1',	1,	'N'),
('IP1',	2,	'CF'),

('IP2',	0,	'GN'),
('IP2',	1,	'N'),
('IP2',	2,	'CF'),
('IP2',	3,	'GP'),

('IP3',	0,	'GP'),
('IP3',	1,	'N'),
('IP3',	2,	'CF'),
('IP3',	3,	'IP');

;with cteCurr as (
  select ItemID,ItemHistoryID,ItemCode,0 as HistRank from @t1 where ItemHistoryID=0),
cteHist as (
   select ItemID,ItemHistoryID,ItemCode
  ,row_number() over (partition by itemID order by ItemHistoryID desc) as HistRank 
  from @t1 where ItemHistoryID>0),
cteAll as (select * from cteCurr UNION ALL select * from cteHist)

select c.ItemID,c.ItemCode as CurrCode,p.itemCode as PrevCode ,c.ItemHistoryID as HistID,p.ItemHistoryID as PrevHistID
from cteAll c inner join cteAll p on c.itemID=p.itemID and p.histrank=c.histrank+1
where c.itemcode like 'G%' and p.Itemcode like 'C%' 

Open in new window


The result:
the results
0
 

Author Closing Comment

by:Tpaul_10
ID: 40555615
Very accurate and quick help, appreciate it.
Thank You Simon, appreciate all your help with the detailed explanation
0

Featured Post

Simplifying Server Workload Migrations

This use case outlines the migration challenges that organizations face and how the Acronis AnyData Engine supports physical-to-physical (P2P), physical-to-virtual (P2V), virtual to physical (V2P), and cross-virtual (V2V) migration scenarios to address these challenges.

Question has a verified solution.

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

Long way back, we had to take help from third party tools in order to encrypt and decrypt data.  Gradually Microsoft understood the need for this feature and started to implement it by building functionality into SQL Server. Finally, with SQL 2008, …
There have been several questions about Large Transaction Log Files in SQL Server 2008, and how to get rid of them when disk space has become critical. This article will explain how to disable full recovery and implement simple recovery that carries…
Along with being a a promotional video for my three-day Annielytics Dashboard Seminor, this Micro Tutorial is an intro to Google Analytics API data.
The Email Laundry PDF encryption service allows companies to send confidential encrypted  emails to anybody. The PDF document can also contain attachments that are embedded in the encrypted PDF. The password is randomly generated by The Email Laundr…

773 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