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Retrieving the last record in each group
i have 2 tables products and cost
PRODUCT
ProdCode - PK
ProdName
COST
Effectivedate - PK
RetailCOst
Prodcode
i tried this query:
SELECT a.ProdCOde AS id, MAX(EffectiveDate) AS edate, RetailCOst AS retail
FROM cost a
INNER JOIN product b USING (ProdCode)
WHERE EffectiveDate <= '2009-10-01'
GROUP BY a.ProdCode;
uhm yah its showing the right effectivedate but the cost on that specific effectivedate doesnt match.
so i want to select the latest date with the matching cost per item.
for example the date i selected is '2009-12-25' and the records for 1 item are these:
ProdCode |EffectiveDate| Cost
00010000 | 2009-01-05 | 50
00010000 | 2009-05-25 | 48
00010000 | 2010-07-01 | 40
so in result i should get 00010000|2009-05-25|48 because it is lesser than the date on my query and it is the latest for that item. and then i want to to show on my query the latest costs on each product.
hope to hear from you soon! thanks!
You need to use a subquery here:
SELECT maxdates.ProdCode, maxdates.maxDate, cost.RetailCost as retail
SELECT ProdCode, max(EffectiveDate) as maxDate
FROM cost
WHERE EffectiveDate < '2009-10-01'
GROUP BY ProdCode
) maxdates
LEFT JOIN cost ON (maxdates.ProdCode=cost.ProdCode
AND maxdates.maxDate=cost.EffectiveDate)
Explanation:
The inner SELECT gives a list of all Products and their respective maximum EffectiveDates. The join "glues" the retail cost per data entry to the result.
Alternatively, using the old max concat trick should do the trick.
SELECT
p.ProdCode,
SUBSTRING(MAX(CONCAT(d.EffectiveDate, c.RetailCost)), 1, 10) AS date,
SUBSTRING(MAX(CONCAT(d.EffectiveDate, c.RetailCost)), 10, 100) + 0 AS cost
FROM
product p,
cost c
WHERE
p.ProdCode = c.ProdCode AND
c.EffectiveDate < '2009-10-01'
GROUP BY
p.ProdCode
Related
I have two tables that I need to join. I have:
LEFT JOIN AutoBAF on (GETDATE() BETWEEN AutoBAF.FromDate and AutoBAF.ToDate)
and I get the expected result. Now if no matching record is found between the two dates (AutoBAF.FromDate and AutoBAF.ToDate) I would like to join the most recent matching record instead.
Can anyone point me in the right direction.
I am using a MS SQL database hosted in Azure.
Small example:
a small example of what I am trying to achieve:
Table Product:
Product | Description
A | Product A
Table Price
Product | FromDate | ToDate | Price
A | 01-01-20 | 31-01-20 | 100
A | 01-02-20 | 28-02-20 | 110
I need a query that will return the price according to the date returned by GETDATE().
If I run the query 15-01-20 I should get:
Product | Description | Price
A | Product A | 100
If I run the query 15-02-20 I should get:
Product | Description | Price
A | Product A | 110
and finally if I run the query 15-03-20 I will have no price in the Price table. Instead of returning null I would like to "fall back" to the most recent known price instead which in this example is 110
This is not the fastest query cause it joins products with all records with future dates. But if your tables are small, it works.
SELECT product.product, product.description, isnull(pr_curr.price, pr_fut.price) as price
FROM product
left join PRICE pr_curr on product.product=pr_curr.product
and GETDATE() BETWEEN pr_curr.FromDate and pr_curr.ToDate
left join PRICE pr_fut on product.product=pr_fut.product
and GETDATE() < pr_fut.FromDate
where pr_fut.FromDate = (
select min(FromDate) from PRICE dates
where dates.product=pr_fut.product and dates.FromDate>GETDATE()
) or pr_fut.FromDate is null
This looks like SQL Server code, which supports lateral joins via the apply keyword. Assuming you want only one match:
from product p outer apply
(select top (1) ab.*
from autobaf ab
where ab.product = p.product and
getdate() <= ab.todate
order by ab.todate desc
) ab
Note that this correlates on the product, which is not part of your question.
If that is not necessary, then you can use:
from t left join
(select top (1) ab.*
from autobaf ab
where getdate() <= ab.todate
order by ab.todate desc
) ab
on 1 = 1
If you know that there is some record in the past, then you can use cross join instead of left join and dispense with the on clause.
SELECT product.product, product.description, isnull(pr_curr.price, pr_fut.price) as price
FROM product
left join PRICE pr_curr on product.product=pr_curr.product
and GETDATE() BETWEEN pr_curr.FromDate and pr_curr.ToDate
left join PRICE pr_fut on product.product=pr_fut.product
and GETDATE() > pr_fut.FromDate
where pr_fut.FromDate = (
select max(FromDate) from PRICE dates
where dates.product=pr_fut.product and dates.FromDate<GETDATE()
) or pr_fut.FromDate is null
I am using this code for inventory management system, in which i want to retrieve stock in hand date-wise from salestb using Three tables
Table Schema
Productmastertb
prod_id,
Product_name
salesdetailstb
sales_id,
Prod_id,
Prod_qty,
billno
salestb
billno
billdate
I need Result something like this
--------------------------------
Product ID | Product Name | Qty
--------------------------------
1 Mouse 10
2 Keyboard 60
3 Headphone 30
---------------------------------
Hope you will find like below solution (date wise qty):
SELECT pm.product_id
,pm.Product_Name
,SUM(sd.Prod_qty) as Qty
,s.billdate
FROM Productmastertb pm
JOIN salesdetailstb as sd ON sd.product_id = pm.product_id
JOIN salestb as s ON sd.billno = s.billno
GROUP BY pm.product_id, pm.Product_Name, s.billdate
Hope it would be helpful to you !
If its not as per your expectation, kindly provide sample output result with partition by date.
I have two tables:
Sales Orders (SO ) with fields:Part, Due_Date, Qty
Part with fields Part and Stock.
I an trying to write a query that will produce the first occurrence ( by date - SO.Due_Date) that a sales order (SO.Qty) cannot be fulfilled by the stock.
This is easy if there is no stock i.e. Part.Stock=0 or if there is only one sales order for the part (SO.Qty > Part.Stock)
If there are multiple sales orders I only want the first one shown e.g.
Part.Part = Box , Part.Stock = 250
SO.Part | SO.Due_Date | SO.Qty
Box | 26/10/2014 | 100
Box | 27/10/2014 | 100
Box | 28/10/2014 | 100 * Return this row
Box | 29/10/2014 | 100
I think I need a sub query or need to use CTE but I can't work it out unless I use a loop. The tables have thousands of parts and sales orders and I am trying to run this query as quickly as possible.
Many thanks for your help
I assume this is a learning exercise, as no real business would work this way.
Anyway, here is a query to do what you want:
select *
from sales_order as so1
where due_date =
(select min(due_date)
from sales_order as so2
inner join part as p on p.part = so2.part
where so1.part = so2.part
and stock < (
select sum(quantity)
from sales_order as so3
where so3.due_date <= so2.due_date
and so3.part = so2.part
)
)
Which I have put into a working fiddle here: http://sqlfiddle.com/#!2/bd8ab5/1
There are some assumptions such as one order per date, but I believe it answers the question.
A query that uses a self join to calculate the running quantity total for each row and selects the row with the smallest due date having a running total greater than p.stock
select so.part, so.due_date, so.quantity
from sales_order so
join part p on p.part = so.part
join sales_order so2 on so2.part = so.part
and so2.due_date <= so.due_date
where p.part = 'Box'
group by so.part, so.due_date, so.quantity
having sum(so2.quantity) > max(p.stock)
order by so.due_date limit 1
I have a little problem.
My table is:
Bill Product ID Units Sold
----|-----------|------------
1 | 10 | 25
1 | 20 | 30
2 | 30 | 11
3 | 40 | 40
3 | 20 | 20
I want to SELECT the product which has sold the most units; in this sample case, it should be the product with ID 20, showing 50 units.
I have tried this:
SELECT
SUM(pv."Units sold")
FROM
"Products" pv
GROUP BY
pv.Product ID;
But this shows all the products, how can I select only the product with the most units sold?
Leaving aside for the moment the possibility of having multiple products with the same number of units sold, you can always sort your results by the sum, highest first, and take the first row:
SELECT pv."Product ID", SUM(pv."Units sold")
FROM "Products" pv
GROUP BY pv."Product ID"
ORDER BY SUM(pv."Units sold") DESC
LIMIT 1
I'm not quite sure whether the double-quote syntax for column and table names will work - exact syntax will depend on your specific RDBMS.
Now, if you do want to get multiple rows when more than one product has the same sum, then the SQL will become a bit more complicated:
SELECT pv.`Product ID`, SUM(pv.`Units sold`)
FROM `Products` pv
GROUP BY pv.`Product ID`
HAVING SUM(pv.`Units sold`) = (
select max(sums)
from (
SELECT SUM(pv2.`Units sold`) as "sums"
FROM `Products` pv2
GROUP BY pv2.`Product ID`
) as subq
)
Here's the sqlfiddle
SELECT SUM(pv."Units sold") as `sum`
FROM "Products" pv
group by pv.Product ID
ORDER BY sum DESC
LIMIT 1
limit 1 + order by
The Best and effective way to this is Max function
Here's The General Syntax of Max function
SELECT MAX(ID) AS id
FROM Products;
and in your Case
SELECT MAX(Units Sold) from products
Here is the Complete Reference to MIN and MAX functions in Query
Click Here
I'm trying to generate a sales reports which lists each product + total sales in a given month. Its a little tricky because the prices of products can change throughout the month. For example:
Between Jan-01 and Jan-15, my company sells 50 Widgets at a cost of $10 each
Between Jan-15 and Jan-31, my company sells 50 more Widgets at a cost of $15 each
The total sales of Widgets for January = (50 * 10) + (50 * 15) = $1250
This setup is represented in the database as follows:
Sales table
Sale_ID ProductID Sale_Date
1 1 2009-01-01
2 1 2009-01-01
3 1 2009-01-02
...
50 1 2009-01-15
51 1 2009-01-16
52 1 2009-01-17
...
100 1 2009-01-31
Prices table
Product_ID Sale_Date Price
1 2009-01-01 10.00
1 2009-01-16 15.00
When a price is defined in the prices table, it is applied to all products sold with the given ProductID from the given SaleDate going forward.
Basically, I'm looking for a query which returns data as follows:
Desired output
Sale_ID ProductID Sale_Date Price
1 1 2009-01-01 10.00
2 1 2009-01-01 10.00
3 1 2009-01-02 10.00
...
50 1 2009-01-15 10.00
51 1 2009-01-16 15.00
52 1 2009-01-17 15.00
...
100 1 2009-01-31 15.00
I have the following query:
SELECT
Sale_ID,
Product_ID,
Sale_Date,
(
SELECT TOP 1 Price
FROM Prices
WHERE
Prices.Product_ID = Sales.Product_ID
AND Prices.Sale_Date < Sales.Sale_Date
ORDER BY Prices.Sale_Date DESC
) as Price
FROM Sales
This works, but is there a more efficient query than a nested sub-select?
And before you point out that it would just be easier to include "price" in the Sales table, I should mention that the schema is maintained by another vendor and I'm unable to change it. And in case it matters, I'm using SQL Server 2000.
If you start storing start and end dates, or create a view that includes the start and end dates (you can even create an indexed view) then you can heavily simplify your query. (provided you are certain there are no range overlaps)
SELECT
Sale_ID,
Product_ID,
Sale_Date,
Price
FROM Sales
JOIN Prices on Sale_date > StartDate and Sale_Date <= EndDate
-- careful not to use between it includes both ends
Note:
A technique along these lines will allow you to do this with a view. Note, if you need to index the view, it will have to be juggled around quite a bit ..
create table t (d datetime)
insert t values(getdate())
insert t values(getdate()+1)
insert t values(getdate()+2)
go
create view myview
as
select start = isnull(max(t2.d), '1975-1-1'), finish = t1.d from t t1
left join t t2 on t1.d > t2.d
group by t1.d
select * from myview
start finish
----------------------- -----------------------
1975-01-01 00:00:00.000 2009-01-27 11:12:57.383
2009-01-27 11:12:57.383 2009-01-28 11:12:57.383
2009-01-28 11:12:57.383 2009-01-29 11:12:57.383
It's well to avoid these types of correlated subqueries. Here's a classic technique for such cases.
SELECT
Sale_ID,
Product_ID,
Sale_Date,
p1.Price
FROM Sales AS s
LEFT JOIN Prices AS p1 ON s.ProductID = p1.ProductID
AND s.Sale_Date >= p1.Sale_Date
LEFT JOIN Prices AS p2 ON s.ProductID = p2.ProductID
AND s.Sale_Date >= p2.Sale_Date
AND p2.Sale_Date > p1.Sale_Date
WHERE p2.Price IS NULL -- want this one not to be found
Use a left outer join on the pricing table as p2, and look for a NULL record demonstrating that the matched product-price record found in p1 is the most recent on or before the sales date.
(I would have inner-joined the first price match, but if there is none, it's nice to have the product show up anyway so you know there's a problem.)
Are you actually running into performance problems or are you just anticipating them? I would implement this exactly as you have, were my hands tied from a schema-modification standpoint as yours are.
I agreee with Sean. The code you have written is very clean and understandable. If you are having performance issues, then take the extra effort to make the code faster. Otherwise, you are making the code more complex for no reason. Nested sub-selects are extremely useful when used judiciously.
The combination of Product_ID and Sale_Date is your foreign key. Try a select-join on Product_ID, Sale_Date.