Counting regardless if match exists or not

SQLServerCentral is supported by Red Gate Software Ltd.

Popular Topics

Home

Members

Calendar

Who's On

Home » SQL Server 7,2000 » General » Counting regardless if match exists or not

Counting regardless if match exists or not

Rate Topic

Display Mode

Topic Options

Author

Message

royer5563

Posted Friday, July 17, 2009 11:29 AM

Forum Newbie

Group: General Forum Members
Last Login: Tuesday, March 12, 2013 9:08 AM
Points: 2, Visits: 51

I've tried hunting for this, but maybe I'm just wording it wrong.

Can anyone help with trying to count records, regardless of whether a match exists or not?

Basics:
PRODUCT Table:
PRODUCT_ID
PRODUCT NAME

MANUFACTURER table:
MANU_ID
MANU_NAME

RETURN_TYPE table:
RETURN_TYPE_ID
RETURN_TYPE

RETURNS Table:
RETURNS_ID
RETURN_DATE
RETURN_TYPE_ID
PRODUCT_ID
MANU_NAME

In this, I have a table showing returns over a given period.
I have a pre-defined listing of products and manufacturers (any manufacturer can produce any of the products given)
(Example, Hard Drive can be produced by Samsung, Maxtor, etc...)

What I am looking to do is get an output that shows ALL products, by all potential manufacturers that MAY have been returned under a given type (if there were no returns, I still want to see that combination as a "0" element).

Output sample:
(RETURN TYPES)
EXCHANGE UPGRADE BUYER REMORSE
Hard Drive SAMSUNG 0 5 1
Hard Drive MAXTOR 3 0 0
Hard Drive SEAGATE 0 0 0

As it sits, I am running this in a looping process where I first build a "SUM(CASE WHEN" block for the "return types".
I then get the "product types" and looping through that,
Get each "manufacturer" and then run a 1 line at a time SQL that looks like:
SELECT PRODUCT, MANUFACTURER, SUM(CASE WHEN PRODUCT=x aND MANU=y THEN 1 else 0 END) as "EXCHANGE"

This seems extremely ineffecient in that if I have 5 products and 5 manufacturers, I am running 25 different SQL statemetns to build my results (results are output througha web page, so I build one line at a time, tack it onto the previous results, then continue).

My thinking is that there must be a way to do something like left outer join on the products->Manufacturers->Returns to get this same info (get ALL products, regardless of whether there is a manufacturer, regardless of whether there is a return or not).

The "sum case" is the easiest part, but I'm totally lost on getting the left-side items.

HELP!!!!! (and if this info is out there, please let me know what conditions you used to search - I've been hunting for the last 2 days and my brain is frazzled).

Post #755032

Allister Reid

Posted Friday, July 17, 2009 11:50 AM

SSC-Enthusiastic

Group: General Forum Members
Last Login: Friday, February 01, 2013 3:19 AM
Points: 192, Visits: 3,071

Hello,
It looks as if it should be a fairly easy solution, but without some table structures and some sample data it is difficult to help! See http://www.sqlservercentral.com/articles/Best+Practices/61537/ on how to post ddls and sample data.

That said, it looks as if you are over-complicating the sum case part, you should only need to do one sum case per column in you output, in fact because you are applying no other criteria than manufacturer and product, you probably only need a count(*) function, but I don't think this is the whole story as you have specified "EXCHANGE UPGRADE BUYER REMORSE" in the output — however, there are seemingly only 3 calculated columns in the output... what criteria are these other columns being calculated on?

For just the straight count you will need something like (note this is TOTALLY untested and probably won't run as-is! need sample data to test)

SELECT 
  Product.ProductName, 
  Returns.Manu_Name, -- Why manufacturer name in returns table - not normalised?
  COALESCE(COUNT(DISTINCT Returns.Returns_ID), 0) AS Exchange
FROM Product
LEFT JOIN Returns ON Product.Product_ID = Returns.Product_ID
GROUP BY Product.ProductName, Returns.Manu_Name

Apologies if this response is unclear, please provide create table code, and sample data in readily consumable format (see link above) and someone will be be able to help!

Hope this gets you a bit further along.

Allister

/// edit added disclaimer on untested code

Post #755045

royer5563

Posted Saturday, July 18, 2009 1:10 AM

Forum Newbie

Group: General Forum Members
Last Login: Tuesday, March 12, 2013 9:08 AM
Points: 2, Visits: 51

THanks for the info - I'll get a better structure put together.

Th very basics of this was only shown - The "returns" tables actualyl consists of much more, but I have a view that consolidates it into the basic details I need to see.

Waht we are looking for in the end is to do a monthly report showing the products that COULD have been returned (differnet receivers, with different types of returns based on the customer type).

A generic cross-tab would typically be sufficient, however, based ont eh nature of the report, they want to know for a fact that we did NOT get a product/manufacturer in by showing the value as a 0 count.

(seems a bit backwards to me - wold be easier to do a cross-tab and then direct export it to a master Excel file with vlookups, but this is not what they bosses want to do.

As stated, I'll put together the stures as we are dealing with it and some raw data to give a better idea of what we are needing to see (and yes, I know the details I posted here are differnet from the display I was showing, but it's the same concept - just different "categories").

Post #755241

« Prev Topic | Next Topic »

Permissions