SQL query to get latest prices, depending on the date - sql-server-2008

I am trying to retrieve a list of products which have been updated, the table contains multiple updates of the products as it records the price changes.
I need to get the latest price changes for all products, but only return the the last update. I have the below code so far, but it only returns the very last update and only 1 product.
SELECT dbo.twProducts.title, dbo.LowestPrices.productAsin, dbo.twProducts.sku,
dbo.LowestPrices.tweAmzPrice, dbo.LowestPrices.price, dbo.LowestPrices.priceDate
FROM dbo.aboProducts INNER JOIN
dbo.LowestPrices ON dbo.aboProducts.asin = dbo.LowestPrices.productAsin
INNER JOIN dbo.twProducts ON dbo.aboProducts.sku = dbo.twProducts.sku
WHERE (dbo.LowestPrices.priceDate =
(SELECT MAX(priceDate) AS Expr1
FROM dbo.LowestPrices AS LowestPrices_1))
I hope this makes sense, i am not sure if i have explained it in a way thats easy to understand.
Any questions please feel free to ask.

The easiest would be to use a CTE with ROW_NUMBER function:
WITH CTE AS
(
SELECT dbo.twProducts.title, dbo.LowestPrices.productAsin, dbo.twProducts.sku,
dbo.LowestPrices.tweAmzPrice, dbo.LowestPrices.price, dbo.LowestPrices.priceDate,
RN = ROW_NUMBER()OVER( PARTITION BY productAsin ORDER BY priceDate DESC)
FROM dbo.aboProducts INNER JOIN
dbo.LowestPrices ON dbo.aboProducts.asin = dbo.LowestPrices.productAsin
INNER JOIN dbo.twProducts ON dbo.aboProducts.sku = dbo.twProducts.sku
)
SELECT * FROM CTE WHERE RN = 1

I think the adjustment to the query you are looking for is to join your subquery rather than just matching on the Date.
SELECT dbo.twProducts.title, dbo.LowestPrices.productAsin, dbo.twProducts.sku,
dbo.LowestPrices.tweAmzPrice, dbo.LowestPrices.price, dbo.LowestPrices.priceDate
FROM dbo.aboProducts INNER JOIN
dbo.LowestPrices ON dbo.aboProducts.asin = dbo.LowestPrices.productAsin
INNER JOIN dbo.twProducts ON dbo.aboProducts.sku = dbo.twProducts.sku
WHERE dbo.LowestPrices.priceDate IN
(SELECT MAX(LowestPrices_1.priceDate)
FROM dbo.LowestPrices AS LowestPrices_1
WHERE dbo.LowestPrices.productAsin = LowestPrices_1.productAsin)
This will match on the max(priceDate) for each product

Related

Left join sql query

I want to get all the data from the users table & the last record associated with him from my connection_history table , it's working only when i don't add at the end of my query
ORDER BY contributions DESC
( When i add it , i have only the record wich come from users and not the last connection_history record)
My question is : how i can get the entires data ordered by contributions DESC
SELECT * FROM users LEFT JOIN connections_history ch ON users.id = ch.guid
AND EXISTS (SELECT 1
FROM connections_history ch1
WHERE ch.guid = ch1.guid
HAVING Max(ch1.date) = ch.date)
The order by should not affect the results that are returned. It only changes the ordering. You are probably getting what you want, just in an unexpected order. For instance, your query interface might be returning a fixed number of rows. Changing the order of the rows could make it look like the result set is different.
I will say that I find = to be more intuitive than EXISTS for this purpose:
SELECT *
FROM users u LEFT JOIN
connections_history ch
ON u.id = ch.guid AND
ch.date = (SELECT Max(ch1.date)
FROM connections_history ch1
WHERE ch.guid = ch1.guid
)
ORDER BY contributions DESC;
The reason is that the = is directly in the ON clause, so it is clear what the relationship between the tables is.
For your casual consideration, a different formatting of the original code. Note in particular the indented AND suggests the clause is part of the LEFT JOIN, which it is.
SELECT * FROM users
LEFT JOIN connections_history ch ON
users.id = ch.guid
AND EXISTS (SELECT 1
FROM connections_history ch1
WHERE ch.guid = ch1.guid
HAVING Max(ch1.date) = ch.date
)
We can use nested queries to first check for max_date for a given user and pass the list of guid to the nested query assuming all the users has at least one record in the connection history table otherwise you could use Left Join instead.
select B.*,X.* from users B JOIN (
select A.* from connection_history A
where A.guid = B.guid and A.date = (
select max(date) from connection_history where guid = B.guid) )X on
X.guid = B.guid
order by B.contributions DESC;

SQL Performing self join to retrieve the current and the immediate previous record by date

I've been trying to retrieve the current and previous record as a single row. I need to get the immediate record before the current one to compare the location of both rows.
Select
CurrentMovement.Location, CurrentMovement.EffectiveDate
, PreviousMovement.Location, PreviousMovement.EffectiveDate
From Product product
Inner join ProductMovement CurrentMovement ON product.Id = CurrentMovement.ProductId
And CurrentMovement.EffectiveDate = (Select Max(EffectiveDate)
From ProductMovement
Where ProductId = product.ProductId)
Inner join ProductMovement PreviousMovement ON PreviousMovement.ProductId = CurrentMovement.ProductId
And PreviousMovement.EffectiveDate < CurrentMovement.EffectiveDate
Where CurrentMovement.Locations != PreviousMovement.Location
I was able to retrieve the current record on the CurrentMovement inner join.
The problem is determining the previous record on the next inner join as I need to retrieve the Max(EffectiveDate) of the previous records that are less than the CurrentMovement.EffectiveDate.
Thanks for the help in advance.
The trick is to assign sequential row numbers and join using this row number. Like so:
WITH PM AS(
SELECT *
, RN = ROW_NUMBER() OVER(PARTITION BY ProductId ORDER BY EffectiveDate DESC)
FROM ProductMovement
)
Select
PMC.Location, PMC.EffectiveDate
, PMP.Location, PMP.EffectiveDate
From Product AS P
INNER join PM AS PMC
ON P.Id = PMC.ProductId
AND PMC.RN = 1
LEFT JOIN PM ON PMP
ON P.Id= PMP.ProductId
AND PMP.RN - 1 = PMC.RN

How to access parent column from a subquery within a join

I'm trying to left join the second table useri_ban based on the users' ids, with the extra condition: useri_ban.start_ban = max_start.
In order for me to calculate max_start, I have to run the following subquery:
(SELECT MAX(ub.start_ban) AS max_start, user_id FROM useri_ban ub WHERE ub.user_id = useri.id)
Furthermore, in order to add max_start to every row, I need to inner join this subquery's result into the main result. However, it seems that once I apply that join, the subquery is no longer able to access useri.id.
What am I doing wrong?
SELECT
useri.id as id,
useri.email as email,
useri_ban.warning_type_id as warning_type_id,
useri_ban.type as type,
useri.created_at AS created_at
FROM `useri`
inner join
(SELECT MAX(ub.start_ban) AS max_start, user_id FROM useri_ban ub WHERE ub.user_id = useri.id) `temp`
on `useri`.`id` = `temp`.`user_id`
left join `useri_ban` on `useri_ban`.`user_id` = `useri`.`id` and `useri_ban`.`start_ban` = `max_start`
Does this solve your problem? You need GROUP BY in the inner query instead of another join.
SELECT useri.id, useri.email, maxQuery.maxStartBan
FROM useri
INNER JOIN
(
SELECT useri_ban.user_id ubid, MAX(useri_ban.startban) maxStartBan
FROM useri_ban
GROUP BY useri_ban.user_id
) AS maxQuery
ON maxQuery.ubid = useri.id;

MAX() Function not working as expected

I've created sqlfiddle to try and get my head around this http://sqlfiddle.com/#!2/21e72/1
In the query, I have put a max() on the compiled_date column but the recommendation column is still coming through incorrect - I'm assuming that a select statement will need to be inserted on line 3 somehow?
I've tried the examples provided by the commenters below but I think I just need to understand this from a basic query to begin with.
As others have pointed out, the issue is that some of the select columns are neither aggregated nor used in the group by clause. Most DBMSs won't allow this at all, but MySQL is a little relaxed on some of the standards...
So, you need to first find the max(compiled_date) for each case, then find the recommendation that goes with it.
select r.case_number, r.compiled_date, r.recommendation
from reporting r
join (
SELECT case_number, max(compiled_date) as lastDate
from reporting
group by case_number
) s on r.case_number=s.case_number
and r.compiled_date=s.lastDate
Thank you for providing sqlFiddle. But only reporting data is given. we highly appreciate if you give us sample data of whole tables.
Anyway, Could you try this?
SELECT
`case`.number,
staff.staff_name AS ``case` owner`,
client.client_name,
`case`.address,
x.mx_date,
report.recommendation
FROM
`case` INNER JOIN (
SELECT case_number, MAX(compiled_date) as mx_date
FROM report
GROUP BY case_number
) x ON x.case_number = `case`.number
INNER JOIN report ON x.case_number = report.case_number AND report.compiled_date = x.mx_date
INNER JOIN client ON `case`.client_number = client.client_number
INNER JOIN staff ON `case`.staff_number = staff.staff_number
WHERE
`case`.active = 1
AND staff.staff_name = 'bob'
ORDER BY
`case`.number ASC;
Check below query:
SELECT c.number, s.staff_name AS `case owner`, cl.client_name,
c.address, MAX(r.compiled_date), r.recommendation
FROM case c
INNER JOIN (SELECT r.case_number, r.compiled_date, r.recommendation
FROM report r ORDER BY r.case_number, r.compiled_date DESC
) r ON r.case_number = c.number
INNER JOIN client cl ON c.client_number = cl.client_number
INNER JOIN staff s ON c.staff_number = s.staff_number
WHERE c.active = 1 AND s.staff_name = 'bob'
GROUP BY c.number
ORDER BY c.number ASC
SELECT
case.number,
staff.staff_name AS `case owner`,
client.client_name,
case.address,
(select MAX(compiled_date)from report where case_number=case.number),
report.recommendation
FROM
case
INNER JOIN report ON report.case_number = case.number
INNER JOIN client ON case.client_number = client.client_number
INNER JOIN staff ON case.staff_number = staff.staff_number
WHERE
case.active = 1 AND
staff.staff_name = 'bob'
GROUP BY
case.number
ORDER BY
case.number ASC
try this

MySQL Inner Join with where clause sorting and limit, subquery?

Everything in the following query results in one line for each invBlueprintTypes row with the correct information. But I'm trying to add something to it. See below the codeblock.
Select
blueprintType.typeID,
blueprintType.typeName Blueprint,
productType.typeID,
productType.typeName Item,
productType.portionSize,
blueprintType.basePrice * 0.9 As bpoPrice,
productGroup.groupName ItemGroup,
productCategory.categoryName ItemCategory,
blueprints.productionTime,
blueprints.techLevel,
blueprints.researchProductivityTime,
blueprints.researchMaterialTime,
blueprints.researchCopyTime,
blueprints.researchTechTime,
blueprints.productivityModifier,
blueprints.materialModifier,
blueprints.wasteFactor,
blueprints.maxProductionLimit,
blueprints.blueprintTypeID
From
invBlueprintTypes As blueprints
Inner Join invTypes As blueprintType On blueprints.blueprintTypeID = blueprintType.typeID
Inner Join invTypes As productType On blueprints.productTypeID = productType.typeID
Inner Join invGroups As productGroup On productType.groupID = productGroup.groupID
Inner Join invCategories As productCategory On productGroup.categoryID = productCategory.categoryID
Where
blueprints.techLevel = 1 And
blueprintType.published = 1 And
productType.marketGroupID Is Not Null And
blueprintType.basePrice > 0
So what I need to get in here is the following table with the columns below it so I can use the values timestamp and sort the entire result by profitHour
tablename: invBlueprintTypesPrices
columns: blueprintTypeID, timestamp, profitHour
I need this information with the following select in mind. Using a select to show my intention of the JOIN/in-query select or whatever that can do this.
SELECT * FROM invBlueprintTypesPrices
WHERE blueprintTypeID = blueprintType.typeID
ORDER BY timestamp DESC LIMIT 1
And I need the main row from table invBlueprintTypes to still show even if there is no result from the invBlueprintTypesPrices. The LIMIT 1 is because I want the newest row possible, but deleting the older data is not a option since history is needed.
If I've understood correctly I think I need a subquery select, but how to do that? I've tired adding the exact query that is above with a AS blueprintPrices after the query's closing ), but did not work with a error with the
WHERE blueprintTypeID = blueprintType.typeID
part being the focus of the error. I have no idea why. Anyone who can solve this?
You'll need to use a LEFT JOIN to check for NULL values in invBlueprintTypesPrices. To mimic the LIMIT 1 per TypeId, you can use the MAX() or to truly make sure you only return a single record, use a row number -- this depends on whether you can have multiple max time stamps for each type id. Assuming not, then this should be close:
Select
...
From
invBlueprintTypes As blueprints
Inner Join invTypes As blueprintType On blueprints.blueprintTypeID = blueprintType.typeID
Inner Join invTypes As productType On blueprints.productTypeID = productType.typeID
Inner Join invGroups As productGroup On productType.groupID = productGroup.groupID
Inner Join invCategories As productCategory On productGroup.categoryID = productCategory.categoryID
Left Join (
SELECT MAX(TimeStamp) MaxTime, TypeId
FROM invBlueprintTypesPrices
GROUP BY TypeId
) blueprintTypePrice On blueprints.blueprintTypeID = blueprintTypePrice.typeID
Left Join invBlueprintTypesPrices blueprintTypePrices On
blueprintTypePrice.TypeId = blueprintTypePrices.TypeId AND
blueprintTypePrice.MaxTime = blueprintTypePrices.TimeStamp
Where
blueprints.techLevel = 1 And
blueprintType.published = 1 And
productType.marketGroupID Is Not Null And
blueprintType.basePrice > 0
Order By
blueprintTypePrices.profitHour
Assuming you might have the same max time stamp with 2 different records, replace the 2 left joins above with something similar to this getting the row number:
Left Join (
SELECT #rn:=IF(#prevTypeId=TypeId,#rn+1,1) rn,
TimeStamp,
TypeId,
profitHour,
#prevTypeId:=TypeId
FROM (SELECT *
FROM invBlueprintTypesPrices
ORDER BY TypeId, TimeStamp DESC) t
JOIN (SELECT #rn:=0) t2
) blueprintTypePrices On blueprints.blueprintTypeID = blueprintTypePrices.typeID AND blueprintTypePrices.rn=1
You don't say where you are putting the subquery. If in the select clause, then you have a problem because you are returning more than one value.
You can't put this into the from clause directly, because you have a correlated subquery (not allowed).
Instead, you can put it in like this:
from . . .
(select *
from invBLueprintTypesPrices ibptp
where ibtp.timestamp = (select ibptp2.timestamp
from invBLueprintTypesPrices ibptp2
where ibptp.blueprintTypeId = ibptp2.blueprintTypeId
order by timestamp desc
limit 1
)
) ibptp
on ibptp.blueprintTypeId = blueprintType.TypeID
This identifies the most recent records for all the blueprintTypeids in the subquery. It then joins in the one that matches.