In a DB2 Database, I want to do the following simple mathematics using a SQL query:
AvailableStock = SupplyStock - DemandStock
SupplyStock is stored in 1 table in 1 row, let's call this table the Supply table.
So the Supply table has this data:
ProductID | SupplyStock
---------------------
109 10
244 7 edit: exclude this product from the search
DemandStock is stored in a separate table Demand, where demand is logged as each customer logs demand during a customer order journey. Example data from the Demand table:
ProductID | DemandStock
------------------------
109 1
244 4 edit: exclude this product
109 6
109 2
So in our heads, if I want to calculate the AvailableStock for product '109', Supply is 10, Demand for product 109 totals to 9, and so Available stock is 1.
How do I do this in one select query in DB2 SQL?
The knowledge I have so far of some of the imagined steps in PseudoCode:
I select SupplyStock where product ID = '109'
I select sum(DemandStock) where product ID = '109'
I subtract SupplyStock from DemandStock
I present this as a resulting AvailableStock
The results will look like this:
Product ID | AvailableStock
109 9
I'd love to get this selected in one SQL select query.
Edit: I've since received an answer (that was almost perfect) and realised the question missed out some information.
This information:
We need to exclude data from products we don't want to select data for, and we also need to specifically select product 109.
My apologies, this was omitted from the original question.
I've since added a 'where' to select the product and this works for me. But for future sake, perhaps the answer should include this information too.
You do this using a join to bring the tables together and group by to aggregate the results of the join:
select s.ProductId, s.SupplyStock, sum(d.DemandStock),
(s.SupplyStock - sum(d.DemandStock)) as Available
from Supply s left join
Demand d
on s.ProductId = d.ProductId
where s.ProductId = 109
group by s.ProductId, s.SupplyStock;
Related
OrderID CustomerID OrderDate
10308 2 1996-09-18
10309 77 1996-09-19
10310 77 1996-09-20
Customer ID CustomerName Address City
1 Alfreds Maria Anders Berlin
2 Ana D.F. 05021 Mexico
77 Antonio D.F. 05023 Mexico
Question : When inner joining two tables above, I'd like to see the result like below:
CustomerID OrderID
2 10308
77 10309,10310
Are the order of the steps below correct? and could you please instruct me what SQL method are needed for each step?
inner join two tables
merging order id for the same customer id
deleting duplicated rows for the same customer id
Thank you very much!
I've attempted to write a query but I've not managed to get it working correctly.
I'm attempting to retrieve where a specific product has been bought but where it also has been bought with other products. In the case below, I want to find where product A01 has been bought but also when it was bought with other products.
Data (extracted from tables for illustration):
Order | Product
123456 | A01
123457 | A01
123457 | B02
123458 | C03
123459 | A01
123459 | C03
Query which will return all orders with product A01 without showing other products:
SELECT
O.NUMBER
O.DATE
P.NUMBER
FROM
ORDERS O
JOIN PRODUCTS P on P.ID = O.ID
WHERE
P.NUMBER = 'A01'
I've tried to create a sub query which brings back just orders of product A01 but I don't know how to place it in the query for it to return all orders containing product A01 as well as any other product ordered with it.
Any help on this would be very grateful.
Thanks in advance.
You can use conditional SUM to detect if one ORDER group have one ore more 'A01'
CREATE TABLE orders
("Order" int, "Product" varchar(3))
;
INSERT INTO orders
("Order", "Product")
VALUES
(123456, 'A01'),
(123457, 'A01'),
(123457, 'B02'),
(123458, 'C03'),
(123459, 'A01'),
(123459, 'C03')
;
SELECT "Order"
FROM orders
GROUP BY "Order"
HAVING SUM(CASE WHEN "Product" = 'A01' THEN 1 ELSE 0 END) > 0
I appreciated Juan's including the DDL to create the database on my system. By the time I saw it, I'd already done all the same work, except that I got around the reserved word problem by naming that field Order1.
Sadly, I didn't consider that either of the offered queries worked on my system. I used MySQL.
The first one returned the A01 lines of the two orders on which other products were ordered too. I took Alex's purpose to include seeing all items of all orders that included A01. (Perhaps he wants to tell future customers what other products other customers have ordered with A01, and generate sales that way.)
The second one returned the three A01 lines.
Maybe Alex wants:
select *
from orders
where Order1 in (select Order1
from orders
where Product = 'A01')
It outputs all lines of all orders that include A01. The subquery makes a list of all orders with A01. The first query returns all lines of those orders.
In a big database, you might not want to run two queries, but this is the only way I see to get the result I understood Alex wanted. If that is what he wanted, he would have to run a second query once armed with output from the queries offered, so there's no real gain.
Good discussion. Thanks to all!
Use GROUP BY clause along with HAVING like
select "order", Product
from data
group by "order"
having count(distinct product) > 1;
I have two classes Apartment and AdditionalSpace representing tables as below.
Apartment table
ID AREA SOLD
---- ------ ----
1 100 1
2 200 0
AdditionalSpace table
ID AREA APARTMENTID
---- ------ -----------
10 10 1
11 10 1
12 10 1
20 20 2
21 20 2
As you can see Apartment's table has a one-to-many relation with AdditionalSpace table, i.e. Apartment.ID=AdditionalSpace.APARTMENTID.
Question:- How to retrieve total area of a sold apartment including its additional space area.
The SQL which I have used so far to retrieve similar result is :-
select sum(apt.area + ads.adsarea) from apartment apt left outer join (select sum(area) as adsarea, apartmentid from additionalspace group by apartmentid) ads on ads.apartmentid=apt.id where apt.sold=1
I am struggling to find a way in order to implement the above scenario via criteria instead of SQL/HQL. Please suggest. Thanks.
I don't think this is possible in criteria. The closest I can see is to simply get the size of the apartment and the sum of the additional areas as two columns in your result, like this:
Criteria criteria = session.createCriteria(Apartment.class,"a");
criteria.createAlias("additionalSpaces", "ads");
criteria.setProjection(Projections.projectionList()
.add(Projections.property("area"))
.add(Projections.groupProperty("a.id"))
.add(Projections.sum("ads.area")));
Alternatively, if you still want to use Hibernate but are happy to write it in HQL, you can do the following:
select ads.apartment.id,max(a.area)+sum(ads.area)
from Apartment a
join a.additionalSpaces ads
group by ads.apartment.id
This works because HQL allows you to write the + to add together the two projections, but I don't know that an analogous method exists on the projections api.
I have a table that lists lots of item transactions. I need to get the last record for each item (the one dated the latest).
For example my table looks like this:
Item Date TrxLocation
XXXXX 1/1/13 WAREHOUSE
XXXXX 1/2/13 WAREHOUSE
XXXXX 1/3/13 WAREHOUSE
aaaa 1/1/13 warehouse
aaaa 2/1/13 WAREHOUSE
I want the data to come back as follows:
XXXXX 1/3/13 WAREHOUSE
AAAA 2/1/13 WAREHOUSE
I tried doing something like this but it is bringing back the wrong date
select Distinct ITEMNMBR
TRXLOCTN,
DATERECD
from TEST
where DateRecd = (select max(DATERECD)
from TEST)
Any help is appreciated.
You're on the right track. You just need to change your subquery to a correlated subquery, which means that you give it some context to the outer query. If you just run your subquery (select max(DATERECD) from TEST) by itself, what do you get? You get a single date that is the latest date in the whole table, regardless of item. You need to tie the subquery to the outer query by linking on the ITEMNMBR column, like this:
SELECT ITEMNMBR, TRXLOCTN, DATERECD
FROM TEST t
WHERE DateRecd = (
SELECT MAX (DATERECD)
FROM TEST tMax
WHERE tMax.ITEMNMBR = t.ITEMNMBR)
No need for subquery. You are querying a single table and need to select MAX(date) and GROUP BY item and TrxLocation.
SELECT Item, max(DATERECD) AS max_dt_recd, TrxLocation
FROM test
GROUP BY Item, TrxLocation
/
I have the following "COMPANIES_BY_NEWS_REPUTATION" in my JavaDB database (this is some random data just to represent the structure)
COMPANY | NEWS_HASH | REPUTATION | DATE
-------------------------------------------------------------------
Company A | 14676757 | 0.12345 | 2011-05-19 15:43:28.0
Company B | 454564556 | 0.78956 | 2011-05-24 18:44:28.0
Company C | 454564556 | 0.78956 | 2011-05-24 18:44:28.0
Company A | -7874564 | 0.12345 | 2011-05-19 15:43:28.0
One news_hash may relate to several companies while a company can relate to several news_hashes as well. Reputation and date are bound to the news_hash.
What I need to do is calculate the average reputation of last 5 news for every company. In order to do that I somehow feel that I need to user 'order by' and 'offset' in a subquery as shown in the code below.
select COMPANY, avg(REPUTATION) from
(select * from COMPANY_BY_NEWS_REPUTATION order by "DATE" desc
offset 0 rows fetch next 5 row only) as TR group by COMPANY;
However, JavaDB allows neither ORDER BY, nor OFFSET in a subquery. Could anyone suggest a working solution for my problem please?
Which version of JavaDB are you using? According to the chapter TableSubquery in the JavaDB documentation, table subqueries do support order by and fetch next, at least in version 10.6.2.1.
Given that subqueries can be ordered and the size of the result set can be limited, the following (untested) query might do what you want:
select COMPANY, (select avg(REPUTATION)
from (select REPUTATION
from COMPANY_BY_NEWS_REPUTATION
where COMPANY = TR.COMPANY
order by DATE desc
fetch first 5 rows only))
from (select distinct COMPANY
from COMPANY_BY_NEWS_REPUTATION) as TR
This query retrieves all distinct company names from COMPANY_BY_NEWS_REPUTATION, then retrieves the average of the last five reputation rows for each company. I have no idea whether it will perform sufficiently, that will likely depend on the size of your data set and what indexes you have in place.
If you have a list of unique company names in another table, you can use that instead of the select distinct ... subquery to retrieve the companies for which to calculate averages.