SQL Inner Join : DB stuck - sql

I postet this question a few days ago but I didn't explain exactly what I want.
I ask the question better formulated again:
To clarify my problem I added some new information:
I got an MySQL DB with MyISAM tables. The two relevant tables are:
* orders_products: orders_products_id, orders_id, product_id, product_name, product_price, product_name, product_model, final_price, ...
* products: products_id, manufacturers_id, ...
(for full information about the tables see screenshot products (Screenshot) and screenshot orders_products (Screenshot))
Now what I want is this: - Get all Orders who ordered products with manufacturers_id = 1. And the product name of the product of this order (with manufacturers_id = 1). Grouped by orders.
What I did so far is this:
SELECT
op.orders_id,
p.products_id,
op.products_name,
op.products_price,
op.products_quantity
FROM orders_products op , products p
INNER JOIN products
ON op.products_id = p.products_id
WHERE p.manufacturers_id = 1 AND
p.orders_id > 10000
p.orders_id > 10000 for testing to get only a few order_id's. But thies query takes much time to get executed if it even works. Two times the sql server stucked. Where is the mistake?

SELECT
op.orders_id,
p.products_id,
op.products_name,
op.products_price,
op.products_quantity
FROM orders_products op
INNER JOIN products p
ON op.products_id = p.products_id
WHERE p.manufacturers_id = 1 AND
p.orders_id > 10000
YOu had both implicit and explict joins on the products table (Make a note to never again use the implicit join syntax, it is a very bad programmin practice) and looking at the code, I suspect you were getting a cross join.

If you do not have any indexes then the select may be generating many table scans.
It may be that you are getting back a very large result set, that could fill up the temp area, which could explain getting stuck.

Related

If transaction within date range, then return customer name (and not all the transactions!)

This code is taking a significant amount of time to run. It's returning every single transaction within the date range but I just need to know if the customer has had at least one transaction, then include the CustomerID, CustomerName, Type, Sign, ReportingName.
I think I need to GROUP BY 'CustomerID' but again only if there was a transaction within the date range. And of course, I'm sure there is an optimal way to execute the below TSQL because it's quite slow at present.
Thanks in advance for any help!
SELECT [ABC].[dbo].[vwPrimary].[RelatedNameId] AS CustomerID
,[ABC].[dbo].[vwPrimary].[RelatedName] AS CustomerName
,[AFGPurchase].[IvL].[TaxTreatment].[ParticluarType] AS Type
,[AFGPurchase].[IvL].[Product].[Sign] AS [Sign]
,[AFGPurchase].[IvL].[Product].[ReportingName] AS ReportingName
,[AFGPurchase].[IvL].[Transaction].[EffectiveDate] AS 'Date'
FROM (((([AFGPurchase].[IvL].[Account]
INNER JOIN [AFGPurchase].[IvL].[Position] ON [AFGPurchase].[IvL].[Account].[AccountId] = [AFGPurchase].[IvL].[Position].[AccountId])
INNER JOIN [AFGPurchase].[IvL].[Product] ON [AFGPurchase].[IvL].[Position].[ProductID] = [AFGPurchase].[IvL].[Product].[ProductId])
INNER JOIN [ABC].[dbo].[vwPrimary] ON [AFGPurchase].[IvL].[Account].[ReportingEntityId] = [ABC].[dbo].[vwPrimary].[RelatedNameId])
INNER JOIN [AFGPurchase].[IvL].[TaxTreatment] ON [AFGPurchase].[IvL].[Account].[TaxTreatmentId] = [AFGPurchase].[IvL].[TaxTreatment].[TaxTreatmentId])
INNER JOIN [AFGPurchase].[IvL].[Transaction] ON [AFGPurchase].[IvL].[Position].[PositionId] = [AFGPurchase].[IvL].[Transaction].[PositionId]
WHERE ((([AFGPurchase].[IvL].[TaxTreatment].[RegistrationType]) LIKE 'NON%')
AND (([AFGPurchase].[IvL].[Product].[Sign])='XYZ2')
AND (([AFGPurchase].[IvL].[Position].[Quantity])<>0)
AND (([AFGPurchase].[IvL].[Transaction].[EffectiveDate]) between '2021-12-31' and '2022-12-31'))
Check your indexes on fragmentation, to speed up your query. And make sure you have indexes.
If you just need one result, just TOP 1
SELECT TOP 1 [ABC].[dbo].[vwPrimary].[RelatedNameId] AS CustomerID
,[ABC].[dbo].[vwPrimary].[RelatedName] AS CustomerName
,[AFGPurchase].[IvL].[TaxTreatment].[ParticluarType] AS Type
,[AFGPurchase].[IvL].[Product].[Sign] AS [Sign]
,[AFGPurchase].[IvL].[Product].[ReportingName] AS ReportingName
,[AFGPurchase].[IvL].[Transaction].[EffectiveDate] AS 'Date'
FROM (((([AFGPurchase].[IvL].[Account]
INNER JOIN [AFGPurchase].[IvL].[Position] ON [AFGPurchase].[IvL].[Account].[AccountId] = [AFGPurchase].[IvL].[Position].[AccountId])
INNER JOIN [AFGPurchase].[IvL].[Product] ON [AFGPurchase].[IvL].[Position].[ProductID] = [AFGPurchase].[IvL].[Product].[ProductId])
INNER JOIN [ABC].[dbo].[vwPrimary] ON [AFGPurchase].[IvL].[Account].[ReportingEntityId] = [ABC].[dbo].[vwPrimary].[RelatedNameId])
INNER JOIN [AFGPurchase].[IvL].[TaxTreatment] ON [AFGPurchase].[IvL].[Account].[TaxTreatmentId] = [AFGPurchase].[IvL].[TaxTreatment].[TaxTreatmentId])
INNER JOIN [AFGPurchase].[IvL].[Transaction] ON [AFGPurchase].[IvL].[Position].[PositionId] = [AFGPurchase].[IvL].[Transaction].[PositionId]
WHERE ((([AFGPurchase].[IvL].[TaxTreatment].[RegistrationType]) LIKE 'NON%')
AND (([AFGPurchase].[IvL].[Product].[Sign])='XYZ2')
AND (([AFGPurchase].[IvL].[Position].[Quantity])<>0)
AND (([AFGPurchase].[IvL].[Transaction].[EffectiveDate]) between '2021-12-31' and '2022-12-31'))
If you only need to check for the existence of a row, and not actually get any data from it then use EXISTS() rather than INNER JOIN, e.g.
SELECT vpr.[RelatedNameId] AS CustomerID
,vpr.[RelatedName] AS CustomerName
,tt.[ParticluarType] AS Type
,prd.[Sign]
,prd.ReportingName
,tr.[EffectiveDate] AS [Date]
FROM [AFGPurchase].[IvL].[Account] AS acc
INNER JOIN [AFGPurchase].[IvL].[Position] AS pos ON acc.[AccountId] = pos.[AccountId]
INNER JOIN [AFGPurchase].[IvL].[Product] AS prd ON pos.[ProductID] = prd.[ProductId]
INNER JOIN [ABC].[dbo].[vwPrimary] AS vpr ON acc.[ReportingEntityId] = vpr.[RelatedNameId]
INNER JOIN [AFGPurchase].[IvL].[TaxTreatment] AS tt ON acc.[TaxTreatmentId] = tt.[TaxTreatmentId]
WHERE tt.[RegistrationType] LIKE 'NON%'
AND prd.[Sign]='XYZ2'
AND pos.[Quantity]<>0
AND EXISTS
( SELECT 1
FROM [AFGPurchase].[IvL].[Transaction] AS tr
WHERE tr.[PositionId] = pos.[PositionId]
AND tr.[EffectiveDate] BETWEEN '2021-12-31' AND '2022-12-31'
);
N.B. I have added in table aliases and removed all the unnecessary parentheses for readability - you may disagree that it is more readable, but I would expect that most people would agree
This may not offer any performance benefits over simply grouping by the columns you are selecting and keeping your joins as they are - SQL is after all a declarative language where you tell the engine what you want, not how to get it. So you may find that the two plans are the same because you are requesting the same result. Using EXISTS does have the advance of being more semantically tied to what you are trying to do though, so gives the optimiser the best chance of getting to the right plan. If you are still having performance issues, then you may need to inspect the execution plan, and see if it suggests any indexes.
Finally, if you are really still using SQL Server 2008 then you really need to start thinking about your upgrade path. It has been completely unsupported for over 3 years now.

SQL - join three tables based on (different) latest dates in two of them

Using Oracle SQL Developer, I have three tables with some common data that I need to join.
Appreciate any help on this!
Please refer to https://i.stack.imgur.com/f37Jh.png for the input and desired output (table formatting doesn't work on all tables).
These tables are made up in order to anonymize them, and in reality contain other data with millions of entries, but you could think of them as representing:
Product = Main product categories in a grocery store.
Subproduct = Subcategory products to the above. Each time the table is updated, the main product category may loses or get some new suproducts assigned to it. E.g. you can see that from May to June the Pulled pork entered while the Fishsoup was thrown out.
Issues = Status of the products, for example an apple is bad if it has brown spots on it..
What I need to find is: for each P_NAME, find the latest updated set of subproducts (SP_ID and SP_NAME), and append that information with the latest updated issue status (STATUS_FLAG).
Please note that each main product category gets its set of subproducts updated at individual occasions i.e. 1234 and 5678 might be "latest updated" on different dates.
I have tried multiple queries but failed each time. I am using combos of SELECT, LEFT OUTER JOIN, JOIN, MAX and GROUP BY.
Latest attempt, which gives me the combo of the first two tables, but missing the third:
SELECT
PRODUCT.P_NAME,
SUBPRODUCT.SP_PRODUCT_ID, SUBPRODUCT.SP_NAME, SUBPRODUCT.SP_ID, SUPPRODUCT.SP_VALUE_DATE
FROM SUBPRODUCT
LEFT OUTER JOIN PRODUCT ON PRODUCT.P_ID = SUBPRODUCT.SP_PRODUCT_ID
JOIN(SELECT SP_PRODUCT_ID, MAX(SP_VALUE_DATE) AS latestdate FROM SUBPRODUCT GROUP BY SP_PRODUCT_ID) sub ON
sub.SP_PRODUCT_ID = SUBPRODUCT.SP_PRODUCT_ID AND sub.latestDate = SUBPRODUCT.SP_VALUE_DATE;
Trying to find a row with a max value is a common SQL pattern - you can do it with a join, like your example, but it's usually more clear to use a subquery or a window function.
Correlated subquery example
select
PRODUCT.P_NAME,
SUBPRODUCT.SP_PRODUCT_ID, SUBPRODUCT.SP_NAME, SUBPRODUCT.SP_ID, SUPPRODUCT.SP_VALUE_DATE,
ISSUES.STATUS_FLAG, ISSUES.STATUS_LAST_UPDATED
from PRODUCT
join SUBPRODUCT
on PRODUCT.P_ID = SUBPRODUCT.SP_PRODUCT_ID
and SUBPRODUCT.SP_VALUE_DATE = (select max(S2.SP_VALUE_DATE) as latestDate
from SUBPRODUCT S2
where S2.SP_PRODUCT_ID = SUBPRODUCT.SP_PRODUCT_ID)
join ISSUES
on ISSUES.ISSUE_ID = SUBPRODUCT.SP_ID
and ISSUES.STATUS_LAST_UPDATED = (select max(I2.STATUS_LAST_UPDATED) as latestDate
from ISSUES I2
where I2.ISSUE_ID = ISSUES.ISSUE_ID)
Window function / inline view example
select
PRODUCT.P_NAME,
S.SP_PRODUCT_ID, S.SP_NAME, S.SP_ID, S.SP_VALUE_DATE,
I.STATUS_FLAG, I.STATUS_LAST_UPDATED
from PRODUCT
join (select SUBPRODUCT.*,
max(SP_VALUE_DATE) over (partition by SP_PRODUCT_ID) as latestDate
from SUBPRODUCT) S
on PRODUCT.P_ID = S.SP_PRODUCT_ID
and S.SP_VALUE_DATE = S.latestDate
join (select ISSUES.*,
max(STATUS_LAST_UPDATED) over (partition by ISSUE_ID) as latestDate
from ISSUES) I
on I.ISSUE_ID = S.SP_ID
and I.STATUS_LAST_UPDATED = I.latestDate
This often performs a bit better, but window functions can be tricky to understand.

Timeout running SQL query

I'm trying to using the aggregation features of the django ORM to run a query on a MSSQL 2008R2 database, but I keep getting a timeout error. The query (generated by django) which fails is below. I've tried running it directs the SQL management studio and it works, but takes 3.5 min
It does look it's aggregating over a bunch of fields which it doesn't need to, but I wouldn't have though that should really cause it to take that long. The database isn't that big either, auth_user has 9 records, ticket_ticket has 1210, and ticket_watchers has 1876. Is there something I'm missing?
SELECT
[auth_user].[id],
[auth_user].[password],
[auth_user].[last_login],
[auth_user].[is_superuser],
[auth_user].[username],
[auth_user].[first_name],
[auth_user].[last_name],
[auth_user].[email],
[auth_user].[is_staff],
[auth_user].[is_active],
[auth_user].[date_joined],
COUNT([tickets_ticket].[id]) AS [tickets_captured__count],
COUNT(T3.[id]) AS [assigned_tickets__count],
COUNT([tickets_ticket_watchers].[ticket_id]) AS [tickets_watched__count]
FROM
[auth_user]
LEFT OUTER JOIN [tickets_ticket] ON ([auth_user].[id] = [tickets_ticket].[capturer_id])
LEFT OUTER JOIN [tickets_ticket] T3 ON ([auth_user].[id] = T3.[responsible_id])
LEFT OUTER JOIN [tickets_ticket_watchers] ON ([auth_user].[id] = [tickets_ticket_watchers].[user_id])
GROUP BY
[auth_user].[id],
[auth_user].[password],
[auth_user].[last_login],
[auth_user].[is_superuser],
[auth_user].[username],
[auth_user].[first_name],
[auth_user].[last_name],
[auth_user].[email],
[auth_user].[is_staff],
[auth_user].[is_active],
[auth_user].[date_joined]
HAVING
(COUNT([tickets_ticket].[id]) > 0 OR COUNT(T3.[id]) > 0 )
EDIT:
Here are the relevant indexes (excluding those not used in the query):
auth_user.id (PK)
auth_user.username (Unique)
tickets_ticket.id (PK)
tickets_ticket.capturer_id
tickets_ticket.responsible_id
tickets_ticket_watchers.id (PK)
tickets_ticket_watchers.user_id
tickets_ticket_watchers.ticket_id
EDIT 2:
After a bit of experimentation, I've found that the following query is the smallest that results in the slow execution:
SELECT
COUNT([tickets_ticket].[id]) AS [tickets_captured__count],
COUNT(T3.[id]) AS [assigned_tickets__count],
COUNT([tickets_ticket_watchers].[ticket_id]) AS [tickets_watched__count]
FROM
[auth_user]
LEFT OUTER JOIN [tickets_ticket] ON ([auth_user].[id] = [tickets_ticket].[capturer_id])
LEFT OUTER JOIN [tickets_ticket] T3 ON ([auth_user].[id] = T3.[responsible_id])
LEFT OUTER JOIN [tickets_ticket_watchers] ON ([auth_user].[id] = [tickets_ticket_watchers].[user_id])
GROUP BY
[auth_user].[id]
The weird thing is that if I comment out any two lines in the above, it runs in less that 1s, but it doesn't seem to matter which lines I remove (although obviously I can't remove a join without also removing the relevant SELECT line).
EDIT 3:
The python code which generated this is:
User.objects.annotate(
Count('tickets_captured'),
Count('assigned_tickets'),
Count('tickets_watched')
)
A look at the execution plan shows that SQL Server is first doing a cross-join on all the table, resulting in about 280 million rows, and 6Gb of data. I assume that this is where the problem lies, but why is it happening?
SQL Server is doing exactly what it was asked to do. Unfortunately, Django is not generating the right query for what you want. It looks like you need to count distinct, instead of just count: Django annotate() multiple times causes wrong answers
As for why the query works that way: The query says to join the four tables together. So say an author has 2 captured tickets, 3 assigned tickets, and 4 watched tickets, the join will return 2*3*4 tickets, one for each combination of tickets. The distinct part will remove all the duplicates.
what about this?
SELECT auth_user.*,
C1.tickets_captured__count
C2.assigned_tickets__count
C3.tickets_watched__count
FROM
auth_user
LEFT JOIN
( SELECT capturer_id, COUNT(*) AS tickets_captured__count
FROM tickets_ticket GROUP BY capturer_id ) AS C1 ON auth_user.id = C1.capturer_id
LEFT JOIN
( SELECT responsible_id, COUNT(*) AS assigned_tickets__count
FROM tickets_ticket GROUP BY responsible_id ) AS C2 ON auth_user.id = C2.responsible_id
LEFT JOIN
( SELECT user_id, COUNT(*) AS tickets_watched__count
FROM tickets_ticket_watchers GROUP BY user_id ) AS C3 ON auth_user.id = C3.user_id
WHERE C1.tickets_captured__count > 0 OR C2.assigned_tickets__count > 0
--WHERE C1.tickets_captured__count is not null OR C2.assigned_tickets__count is not null -- also works (I think with beter performance)

BigQuery - Shuffle By error

I have a table of about 5M rows. Note this is just a poc. Ultimately we will need to be in the TB range. I am doing a self join to find permutations of products for a market basket analysis.
I need to find the number of times the combination occurs in a basket, the ratio of occurrences to total baskets, and the number of times the item occurs in all baskets. This is pretty standard. BigQuery does not support selects in the predicate of another select so I needed to create another join I suppose. Here's what I came up with -
select twoItem.upc1,twoItem.upc2,twoItem.twoItemOccurrences, totalUpc.totalUpcCount
from
(
select purchase1.upc as upc1,purchase2.upc as upc2,count(upc1) as twoItemOccurrences
from
conagra.purchase as purchase1
join each conagra.purchase as purchase2
on purchase1.upc = purchase2.upc
group by upc1,upc2
) as twoItem
JOIN EACH
(
select purchase3.upc as upc3, count(*) as totalUpcCount
from conagra.purchase as purchase3
group by upc3
) as totalUpc
on totalUpc.upc3 = twoItem.upc1
LIMIT 50;
I get the following error:
SHUFFLE BY may only be applied to parallelizable queries, but query is not parallelizable: (SELECT * FROM (SELECT [purchase3.upc] AS [upc3], COUNT(*) AS [totalUpcCount]...
Maybe an unpublished limitation?
Any help would be appreciated.
Try running these with GROUP EACH BY on your inner queries. We'll improve the response message for queries like this.

SUM(a*b) not working

I have a PHP page running in postgres. I have 3 tables - workorders, wo_parts and part2vendor. I am trying to multiply 2 table column row datas together, ie wo_parts has a field called qty and part2vendor has a field called cost. These 2 are joined by wo_parts.pn and part2vendor.pn. I have created a query like this:
$scoreCostQuery = "SELECT SUM(part2vendor.cost*wo_parts.qty) as total_score
FROM part2vendor
INNER JOIN wo_parts
ON (wo_parts.pn=part2vendor.pn)
WHERE workorder=$workorder";
But if I add the costs of the parts multiplied by the qauntities supplied, it adds to a different number than what the script is doing. Help....I am new to this but if someone can show me in SQL I can modify it for postgres. Thanks
Without seeing example data, there's no way for us to know why you're query totals are coming out differently that when you do the math by hand. It could be a bad join, so you are getting more/less records than you expected. It's also possible that your calculations are off. Pick an example with the smallest number of associated records & compare.
My suggestion is to add a GROUP BY to the query:
SELECT SUM(p.cost * wp.qty) as total_score
FROM part2vendor p
JOIN wo_parts wp ON wp.pn = p.pn
WHERE workorder = $workorder
GROUP BY workorder
FYI: MySQL was designed to allow flexibility in the GROUP BY, while no other db I've used does - it's a source of numerous questions on SO "why does this work in MySQL when it doesn't work on db x...".
To Check that your Quantities are correct:
SELECT wp.qty,
p.cost
FROM WO_PARTS wp
JOIN PART2VENDOR p ON p.pn = wp.pn
WHERE p.workorder = $workorder
Check that the numbers are correct for a given order.
You could try a sub-query instead.
(Note, I don't have a Postgres installation to test this on so consider this more like pseudo code than a working example... It does work in MySQL tho)
SELECT
SUM(p.`score`) AS 'total_score'
FROM part2vendor AS p2v
INNER JOIN (
SELECT pn, cost * qty AS `score`
FROM wo_parts
) AS p
ON p.pn = p2v.pn
WHERE p2n.workorder=$workorder"
In the question, you say the cost column is in part2vendor, but in the query you reference wo_parts.cost. If the wo_parts table has its own cost column, that's the source of the problem.