How to fix this error
Error in query: ERROR: aggregate functions are not allowed in JOIN conditions
this my query
SELECT *
FROM "downloads" dl
inner join access_logs l
on dl.id=l.download_id
and dl.file_id=l.file_id
and dl.site_id=l.site_id
and sum(l.body_bytes_Sent)>dl.filesize
I want the list of all files downloaded completely.
sum(body_bytes_Sent)>=filesize
Seems you are assuming that somehow SQL will know that it should sum somthing - but is has not received any instructions on how to perform the aggregation which requires a group by clause. So, form a complete query and then join it as a "derived table" like this:
SELECT *
FROM downloads dl
inner join (
SELECT download_id, file_id, site_id, sum(l.body_bytes_Sent) AS sum_sent
FROM access_logs
GROUP BY download_id, file_id, site_id
) AS l
on dl.id=l.download_id
and dl.file_id=l.file_id
and dl.site_id=l.site_id
and L.sum_Sent > dl.filesize
As there are no details to hand on the data model, or sample data to inspect, the query above may still require refinement.
Related
The Query (For this question I do not think that you need to see schema):
SELECT Agencies.AgencyName, (SELECT DISTINCT MAX(Invoices.CostsTotal) FROM Invoices WHERE Contracts.ContractID = Invoices.ContractID) AS MaxInvoice
FROM Contracts
LEFT JOIN Agencies ON Contracts.AgencyID = Agencies.AgencyID
ORDER BY MaxInvoice DESC;
How do we order the recordset returned from a query by a field created within that same query?
I have seen the function FIELDS(INDEX) ? But this does not exist in access? Also not sure that it would even work. In this instance I want to sort the recordset by the MaxInvoice field.
MS Access prompts me to enter a parameter value for MaxInvoice when I attempt to run this query
You can write parent SELECT which wraps your current SELECT.
Like this:
SELECT * FROM (
SELECT Agencies.AgencyName,
(SELECT DISTINCT MAX(Invoices.CostsTotal) FROM Invoices
WHERE Contracts.ContractID = Invoices.ContractID) AS MaxInvoice
FROM Contracts LEFT JOIN Agencies
ON Contracts.AgencyID = Agencies.AgencyID
) AS ContractsLargestInvoice
ORDER BY ContractsLargestInvoice.MaxInvoice DESC;
Most SQL dialects support the use of aliases in the ORDER BY. But MS Access is further from SQL standards than most databases.
I would suggest you rewrite the query to move Invoices into the FROM clause -- using aggregation to get what you want:
SELECT a.AgencyName, MAX(i.CostsTotal) AS MaxInvoice
FROM (Contracts as c LEFT JOIN
Agencies as a
ON c.AgencyID = a.AgencyID) LEFT JOIN
Invoices as i
ON i.ContractID = c.ContractID
GROUP BY a.AgencyName
ORDER BY MAX(i.CostsTotal) DESC;
It seems strange that you are using a LEFT JOIN and choosing a field from the second table and not the first. This could be NULL.
This is the schema for my questions
Hi, I don't have experience in SQL Developer and I'm trying to build a query for the following question:
I need that for each DVD in the catalog, display the title, length, release_date, and how many times it has been checked out by all customers across all libraries.
Also I want to include those that have not been checked out yet displaying 0, and sort results by title.
So far I have this in the query but I'm stock here:
--Question C. ************* VERIFY
Select
Catalog_Item.Title,
DVD.Length,
Catalog_Item.Release_Date,
(
Select
Count(Transaction.Transaction_ID)
From Transaction
Where
DVD.Catalog_Item_ID = Physical_Item.Catalog_Item_ID
And Physical_Item.Physical_Item_ID = Transaction.Physical_Item_ID
) as "Total_DVD"
From
Catalog_Item,DVD,
Physical_Item
Group by
Catalog_Item.Title,
DVD.Length,
Catalog_Item.Release_Date
If I run this exact query I get error
Not a Group By Expression
And if I exclude the GROUP BY, I get results by doesn't look like the correct outputs.
Any suggestions on what syntax I can use to achieve the desired output? Thanks!
You put three tables to the query but you missed to link them. If you don't link them, you will see too much-duplicated rows.
Also, your sub-query links were wrong, I assume you tried to put the links here that you missed in the main query.
I believe you need something like that:
Select
CI.Title
,DVD.Length
,CI.Release_Date
,NVL(TR.TotalTransactions,0) TotalTransactions
From Catalog_Item CI
INNER JOIN DVD ON DVD.Catalog_Item_ID = CI.Catalog_Item_ID
LEFT JOIN Physical_Item PHI ON CI.Catalog_Item_ID = PHI.Catalog_Item_ID
LEFT JOIN (SELECT Physical_Item_ID
, Count(Transaction_ID) TotalTransactions
FROM Transaction
GROUP BY Physical_Item_ID
) TR ON PHI.Physical_Item_ID = TR.Physical_Item_ID
For a start, join Catalog_Item, Physical_Item and DVD together. Without appropriate join conditions, these three tables will join using a cartesian product join - which is probably one of the reasons why you are seeing unexpected results.
I am making a subquery but I am getting a strange error
The column 'RealEstateID' was specified multiple times for 'NotSold'.
here is my code
SELECT *
FROM
(SELECT *
FROM RealEstatesInfo AS REI
LEFT JOIN Purchases AS P
ON P.RealEstateID=REI.RealEstateID
WHERE DateBought IS NULL) AS NotSold
INNER JOIN OwnerEstate AS OE
ON OE.RealEstateID=NotSold.RealEstateID
It's on SQL server by the way.
That's because there will be 2 realestiteids in your subquery. You need to change it to explicitly list the columns from both table and only include 1 realestateid. It doesn't matter which as you use it for your join.
If you're very Lazy you can select rei.* and only name the p cols apart from realestateid.
Btw select * is probably never a good idea in sub queries or derived tables or ctes.
I have an SQL question, related to this and this question (but different). Basically I want to know how I can avoid a nested query.
Let's say I have a huge table of jobs (jobs) executed by a company in their history. These jobs are characterized by year, month, location and the code belonging to the tool used for the job. Additionally I have a table of tools (tools), translating tool codes to tool descriptions and further data about the tool. Now they want a website where they can select year, month, location and tool using a dropdown box, after which the matching jobs will be displayed. I want to fill the last dropdown with only the relevant tools matching the before selection of year, month and location, so I write the following nested query:
SELECT c.tool_code, t.tool_description
FROM (
SELECT DISTINCT j.tool_code
FROM jobs AS j
WHERE j.year = ....
AND j.month = ....
AND j.location = ....
) AS c
LEFT JOIN tools as t
ON c.tool_code = t.tool_code
ORDER BY c.tool_code ASC
I resorted to this nested query because it was much faster than performing a JOIN on the complete database and selecting from that. It got my query time down a lot. But as I have recently read that MySQL nested queries should be avoided at all cost, I am wondering whether I am wrong in this approach. Should I rewrite my query differently? And how?
No, you shouldn't, your query is fine.
Just create an index on jobs (year, month, location, tool_code) and tools (tool_code) so that the INDEX FOR GROUP-BY can be used.
The article your provided describes the subquery predicates (IN (SELECT ...)), not the nested queries (SELECT FROM (SELECT ...)).
Even with the subqueries, the article is wrong: while MySQL is not able to optimize all subqueries, it deals with IN (SELECT …) predicates just fine.
I don't know why the author chose to put DISTINCT here:
SELECT id, name, price
FROM widgets
WHERE id IN
(
SELECT DISTINCT widgetId
FROM widgetOrders
)
and why do they think this will help to improve performance, but given that widgetID is indexed, MySQL will just transform this query:
SELECT id, name, price
FROM widgets
WHERE id IN
(
SELECT widgetId
FROM widgetOrders
)
into an index_subquery
Essentially, this is just like EXISTS clause: the inner subquery will be executed once per widgets row with the additional predicate added:
SELECT NULL
FROM widgetOrders
WHERE widgetId = widgets.id
and stop on the first match in widgetOrders.
This query:
SELECT DISTINCT w.id,w.name,w.price
FROM widgets w
INNER JOIN
widgetOrders o
ON w.id = o.widgetId
will have to use temporary to get rid of the duplicates and will be much slower.
You could avoid the subquery by using GROUP BY, but if the subquery performs better, keep it.
Why do you use a LEFT JOIN instead of a JOIN to join tools?
I am attempting to get the information from one table (games) and count the entries in another table (tickets) that correspond to each entry in the first. I want each entry in the first table to be returned even if there aren't any entries in the second. My query is as follows:
SELECT g.*, count(*)
FROM games g, tickets t
WHERE (t.game_number = g.game_number
OR NOT EXISTS (SELECT * FROM tickets t2 WHERE t2.game_number=g.game_number))
GROUP BY t.game_number;
What am I doing wrong?
You need to do a left-join:
SELECT g.Game_Number, g.PutColumnsHere, count(t.Game_Number)
FROM games g
LEFT JOIN tickets t ON g.Game_Number = t.Game_Number
GROUP BY g.Game_Number, g.PutColumnsHere
Alternatively, I think this is a little clearer with a correlated subquery:
SELECT g.Game_Number, G.PutColumnsHere,
(SELECT COUNT(*) FROM Tickets T WHERE t.Game_Number = g.Game_Number) Tickets_Count
FROM Games g
Just make sure you check the query plan to confirm that the optimizer interprets this well.
You need to learn more about how to use joins in SQL:
SELECT g.*, count(*)
FROM games g
LEFT OUTER JOIN tickets t
USING (game_number)
GROUP BY g.game_number;
Note that unlike some database brands, MySQL permits you to list many columns in the select-list even if you only GROUP BY their primary key. As long as the columns in your select-list are functionally dependent on the GROUP BY column, the result is unambiguous.
Other brands of database (Microsoft, Firebird, etc.) give you an error if you list any columns in the select-list without including them in GROUP BY or in an aggregate function.
"FROM games g, tickets t" is the problem line. This performs an inner join. Any where clause can't add on to this. I think you want a LEFT OUTER JOIN.