I've been working on this for far too many hours now and hit the wall. Hoping an SQL guru can help shed some light.
SELECT
CATEGORY.CategoryID, CATEGORY.Category_Name, CATEGORY_SUB.CategoryID AS Expr1,
CATEGORY_SUB.SubCategory_Name, COUNT(SELL_1.Item_SubCategory) AS Count,
(SELECT COUNT(Item_Category) AS Expr10
FROM SELL WHERE (UserName = 'me')
GROUP BY Item_Category) AS Expr20
FROM SELL AS SELL_1 LEFT OUTER JOIN
CATEGORY ON
SELL_1.Item_Category = CATEGORY.Category_Name
LEFT OUTER JOIN CATEGORY_SUB ON
CATEGORY.CategoryID = CATEGORY_SUB.CategoryID AND SELL_1.Item_SubCategory = CATEGORY_SUB.SubCategory_Name WHERE (SELL_1.Seller_UserName = 'me') AND (SELL_1.Item_Removed IS NULL) AND (SELL_1.Item_Pause IS NULL) AND (SELL_1.Item_Expires > GETDATE())
GROUP BY CATEGORY.Category_Name, CATEGORY_SUB.SubCategory_Name, CATEGORY.CategoryID, CATEGORY_SUB.CategoryID
ORDER BY Count DESC
In short the table returned should how the following columns where Expr20 is a "sum" or aggregate of the total counts of CategoryName so for example.
CategoryID CategoryName Expr1 SubCategory_Name Count Expr20
1 CatA 200 SubCatA1 1 1
1 CatA 201 SubCatA2 2 3
1 CatA 202 SubCatA3 4 7
2 CatB 301 SubCatB1 1 1
2 CatB 302 SubCatB2 4 5
3 CatC 401 SubCatC1 3 3
3 CatC 402 SubCatC2 2 5
3 CatC 403 SubCatC3 4 9
And So on.
My problem is no matter what I do I cannot seem to get Expr20 to work.
It seems the problem is with MS SQL wanting the alias after the (SELECT COUNT(Item_Category) so then it throws the error because 2 columns are returned.
I'm running MS SQL 2005. Grateful for any help
Really struggled with this and in the end used maybe a more elegant solution but potentially more server intensive...I'm not sure as I'm no SQL expert...but wanted to post my solution.
SELECT T1.CategoryID, Expr20, etc...
FROM
(
SELECT COUNT(Item_Category)
FROM SELL WHERE (UserName = 'me')
GROUP BY Item_Category) AS Expr20
) T1
JOIN
(
SELECT CATEGORY.CategoryID, CATEGORY.Category_Name, CATEGORY_SUB.CategoryID AS Expr1, CATEGORY_SUB.SubCategory_Name, COUNT(SELL.Item_SubCategory) AS Count...etc as shown in the question) T2
ON T1.Item_Category = T2.Category_Name
ORDER BY T1.Counted DESC
Worked a treat and I got the table and results I needed grouping the category names with the correct number of sum total per line.
So the trick was to make a select around the 2 selects rather than trying to join them as this just doesn't seem possible.
How this helps someone and saves them the 13 hours or hair pulling I went through last night.
It is a bit hard to see what data you are starting with. But, assuming you have all columns except Expr20, you can use outer apply or a correlated subquery:
select t.*, t2.Expr20
from sell t outer apply
(select sum(count) as Expr20
from sell t2
where t2.CategoryId = t.CategoryId and
t2.expr1 <= t.expr1
) t2;
Related
I have a table called 'users' that has the following structure:
id (PK)
campaign_id
createdAt
1
123
2022-07-14T10:30:01.967Z
2
1234
2022-07-14T10:30:01.967Z
3
123
2022-07-14T10:30:01.967Z
4
123
2022-07-14T10:30:01.967Z
At the same time I have a table that tracks clicks per user:
id (PK)
user_id(FK)
createdAt
1
1
2022-07-14T10:30:01.967Z
2
2
2022-07-14T10:30:01.967Z
3
2
2022-07-14T10:30:01.967Z
4
2
2022-07-14T10:30:01.967Z
Both of these table are up to millions of records... I need the most efficient query to group the data per campaign_id.
The result I am looking for would look like this:
campaign_id
total_users
total_clicks
123
3
1
1234
1
3
I unfortunately have no idea how to achieve this while minding performance and most important of it all I need to use WHERE or HAVING to limit the query in a certain time range by createdAt
Note, PostgreSQL is not my forte, nor is SQL. But, I'm learning spending some time on your question. Have a go with INNER JOIN after two seperate SELECT() statements:
SELECT * FROM
(
SELECT campaign_id, COUNT (t1."id(PK)") total_users FROM t1 GROUP BY campaign_id
) tbl1
INNER JOIN
(
SELECT campaign_id, COUNT (t2."user_id(FK)") total_clicks FROM t2 INNER JOIN t1 ON t1."id(PK)" = t2."user_id(FK)" GROUP BY campaign_id
) tbl2
USING(campaign_id)
See an online fiddle. I believe this is now also ready for a WHERE clause in both SELECT statements to filter by "createdAt". I'm pretty sure someone else will come up with something better.
Good luck.
Hope this will help you.
select u.campaign_id,
count(distinct u.id) users_count,
count(c.user_id) clicks_count
from
users u left join clicks c on u.id=c.user_id
group by 1;
See here query output
I've been trying to solve this problem over the weekend, without luck so far. I have two tables:
TopOffers:
OfferId RetailerId Order
1 38 0
2 8 3
3 17 2
4 22 1
And Offers:
Id RetailerId Name Description etc...
1 3 Strawberry Red and smelly
2 38 Cookie Crunchy
3 17 Onion Of the nice kind
4 22 Apple Cheap
5 8 Toothbrush Lasts extra long!
My goal is to get the top 10 Offers for each Retailer ID. The order in which they should be listed is specified by the Order field in the TopOffer table (Sort order is Ascending). On top of that, the result should be padded to 10 offers when there are less than 10 TopOffer records for a retailer. The TopOffer table always contains 10 or less records per retailer.
So far I've managed to get this going, which works (I realize it doesn't get the top 10, but rather everything that's in the TopOffer table, which is alright, since the TopOffer table is always equal to or smaller than the top 10 for any retailer):
SELECT b.*
FROM
(
SELECT o.Id, to.`Order` FROM Offer AS o
LEFT JOIN TopOffer AS to
ON o.Id = to.OfferId
) AS a,
(
SELECT o.*, to.`Order` FROM Offer AS o
LEFT JOIN TopOffer AS to
ON o.Id = to.OfferId
) AS b
WHERE a.`Order` >= b.`Order` AND a.Id = b.Id
GROUP BY b.RetailerId, b.Id
HAVING Count(1) BETWEEN 1 AND 10
ORDER BY RetailerId, `Order` ASC
Unfortunately I can't seem to find any way of padding the result of this query with offers that don't have an entry in the TopOffer table if there aren't 10 TopOffer records for that retailer.
My sincerest thanks in advance for any help!
If you create a virtual table with numbers 1-10 you can left join to your results to get 10 of each
select number, results.*
from
(select 1 as number union select 2 union select 3 ... union select 10) numbers
left join
(your query here) results
on numbers.number = results.rank
I am writing an SQL query which will return a list of auctions a certain user is losing, like on eBay.
This is my table:
bid_id bid_belongs_to_auction bid_from_user bid_price
6 7 1 15.00
8 7 2 19.00
13 7 1 25.00
The problematic area is this (taken from my full query, placed at the end of the question):
AND EXISTS (
SELECT 1
FROM bids x
WHERE x.bid_belongs_to_auction = bids.bid_belongs_to_auction
AND x.bid_price > bids.bid_price
AND x.bid_from_user <> bids.bid_from_user
)
The problem is that the query returns all the auctions on which there are higher bids, but ignoring the user's even higher bids.
So, an example when the above query works:
bid_id bid_belongs_to_auction bid_from_user bid_price
6 7 1 15.00
7 7 2 18.00
In this case, user 1 is returned as losing the auction, because there is another bid higher than the users bid.
But, here is when the query doesn't work:
bid_id bid_belongs_to_auction bid_from_user bid_price
6 7 1 15.00
8 7 2 19.00
13 7 1 25.00
In this case, user 1 is incorrectly returned as losing the auction, because there is another bid higher than one of his previous bids, but the user has already placed a higher bid over that.
If it's important, here's my full query, but I think it won't be necessary to solve the aforementioned problem, but I'm posting it here anyway:
$query = "
SELECT
`bid_belongs_to_auction`,
`auction_unixtime_expiration`,
`auction_belongs_to_hotel`,
`auction_seo_title`,
`auction_title`,
`auction_description_1`
FROM (
SELECT
`bid_belongs_to_auction`,
`bid_from_user`,
MAX(`bid_price`) AS `bid_price`,
`auctions`.`auction_enabled`,
`auctions`.`auction_unixtime_expiration`,
`auctions`.`auction_belongs_to_hotel`,
`auctions`.`auction_seo_title`,
`auctions`.`auction_title`,
`auctions`.`auction_description_1`
FROM `bids`
LEFT JOIN `auctions` ON `auctions`.`auction_id`=`bids`.`bid_belongs_to_auction`
WHERE `auction_enabled`='1' AND `auction_unixtime_expiration` > '$time' AND `bid_from_user`='$userId'
AND EXISTS (
SELECT 1
FROM bids x
WHERE x.bid_belongs_to_auction = bids.bid_belongs_to_auction
AND x.bid_price > bids.bid_price
AND x.bid_from_user <> bids.bid_from_user
)
GROUP BY `bid_belongs_to_auction`
) AS X
WHERE `bid_from_user`='$userId'
";
Here's a different approach:
$query = "
SELECT
`max_bids`.`bid_belongs_to_auction`,
`auctions`.`auction_unixtime_expiration`,
`auctions`.`auction_belongs_to_hotel`,
`auctions`.`auction_seo_title`,
`auctions`.`auction_title`,
`auctions`.`auction_description_1`
FROM `auctions`
INNER JOIN (
SELECT
`bid_belongs_to_auction`,
MAX(`bid_price`) AS `auction_max_bid`,
MAX(CASE `bid_from_user` WHEN '$userId' THEN `bid_price` END) AS `user_max_bid`
FROM `bids`
GROUP BY `bid_belongs_to_auction`
) AS `max_bids` ON `auctions`.`auction_id` = `max_bids`.`bid_belongs_to_auction`
WHERE `auctions`.`auction_enabled`='1'
AND `auctions`.`auction_unixtime_expiration` > '$time'
AND `max_bids`.`user_max_bid` IS NOT NULL
AND `max_bids`.`user_max_bid` <> `max_bids`.`auction_max_bid`
";
Basically, when you are retrieving the max bids for all the auctions, you are also retrieving the specific user's max bids along. Next step is to join the obtained list to the auctions table and apply an additional filter on the user's max bid being not equal to the auction's max bid.
Note: the `max_bids`.`user_max_bid` IS NOT NULL condition might be unnecessary. It would definitely be so in SQL Server, because the non-nullness would be implied by the `max_bids`.`user_max_bid` <> `max_bids`.`auction_max_bid` condition. I'm not sure if it's the same in MySQL.
Untested, but this is how I would approach it. Ought to perform OK if there's an index on userid and also one on auctionid.
select OurUserInfo.auctionid, OurUserInfo.userid,
OurUserInfo.ourusersmaxbid, Winningbids.TopPrice
from
(
select A.auctionid, A.userid, max(A.price) as OurUsersMaxBid
from auctions A where userid = ?
group by A.auctionid, A.userid
) as OurUserInfo
inner join
(
-- get the current winning bids for all auctions in which our user is bidding
select RelevantAuctions.auctionid, max(auctions.price) as TopPrice
from auctions inner join
(
select distinct auctionid from auctions where userid = ? -- get our user's auctions
) as RelevantAuctions
on auctions.auctionid = RelevantAuctions.auctionid
group by RelevantAuctions.auctionid
) as WinninBids
on OurUserInfo.auctionid = winningbids.auctionid
where WinninBids.TopPrice > OurUserInfo.ourusersmaxbid
Instead of
SELECT 1
FROM bids x
WHERE x.bid_belongs_to_auction = bids.bid_belongs_to_auction
AND x.bid_price > bids.bid_price
AND x.bid_from_user <> bids.bid_from_user
try this:
SELECT 1
FROM (SELECT BID_ID,
BID_BELONGS_TO_AUCTION,
BID_FROM_USER,
BID_PRICE
FROM (SELECT BID_ID,
BID_BELONGS_TO_AUCTION,
BID_FROM_USER,
BID_PRICE,
RANK ()
OVER (
PARTITION BY BID_BELONGS_TO_AUCTION, BID_FROM_USER
ORDER BY BID_PRICE DESC)
MY_RANK
FROM BIDS)
WHERE MY_RANK = 1) x
WHERE x.bid_belongs_to_auction = bids.bid_belongs_to_auction
AND x.bid_price > bids.bid_price
AND x.bid_from_user <> bids.bid_from_user;
I have a table called RESULTS with this structure :
resultid,winner,type
And a table called TICKETS with this structure :
resultid,ticketid,bet,sum_won,status
And I want to show each row from table RESULTS and for each result I want to calculate the totalBet and Sum_won using the values from table TICKETS
I tried to make some joins,some sums,but I cant get what I want.
SELECT *,COALESCE(SUM(tickets.bet),0) AS totalbets,
COALESCE(SUM(tickets.sum_won),0) AS totalwins
FROM `results` NATURAL JOIN `tickets`
WHERE tickets.status<>0
GROUP BY resultid
Please give me some advice.
I want to display something like this
RESULT WINNER TOTALBETS TOTALWINS
1 2 431 222
2 3 0 0
3 1 23 0
4 1 324 111
Use:
SELECT r.*,
COALESCE(x.totalbet, 0) AS totalbet,
COALESCE(x.totalwins, 0) AS totalwins
FROM RESULTS r
LEFT JOIN (SELECT t.resultid,
SUM(t.bet) AS totalbet,
SUM(t.sum_won) AS totalwins
FROM TICKETS t
WHERE t.status != 0
GROUP BY t.resultid) x ON x.resultid = r.resultid
I don't care for the NATURAL JOIN syntax, preferring to be explicit about how to JOIN/link tables together.
SELECT *, COALESCE(SUM(tickets.bet),0) AS totalbets,
COALESCE(SUM(tickets.sum_won),0) AS totalwins
FROM `results` NATURAL JOIN `tickets`
WHERE tickets.status<>0
GROUP BY resultid
Try to replace the first * with resultid. If this helps, then add more columns to SELECT and add them to GROUP BY at the same time.
database table like this
============================
= suburb_id | value
= 1 | 2
= 1 | 3
= 2 | 4
= 3 | 5
query is
SELECT COUNT(suburb_id) AS total, suburb_id
FROM suburbs
where suburb_id IN (1,2,3,4)
GROUP BY suburb_id
however, while I run this query, it doesn't give COUNT(suburb_id) = 0 when suburb_id = 0
because in suburbs table, there is no suburb_id 4, I want this query to return 0 for suburb_id = 4, like
============================
= total | suburb_id
= 2 | 1
= 1 | 2
= 1 | 3
= 0 | 4
A GROUP BY needs rows to work with, so if you have no rows for a certain category, you are not going to get the count. Think of the where clause as limiting down the source rows before they are grouped together. The where clause is not providing a list of categories to group by.
What you could do is write a query to select the categories (suburbs) then do the count in a subquery. (I'm not sure what MySQL's support for this is like)
Something like:
SELECT
s.suburb_id,
(select count(*) from suburb_data d where d.suburb_id = s.suburb_id) as total
FROM
suburb_table s
WHERE
s.suburb_id in (1,2,3,4)
(MSSQL, apologies)
This:
SELECT id, COUNT(suburb_id)
FROM (
SELECT 1 AS id
UNION ALL
SELECT 2 AS id
UNION ALL
SELECT 3 AS id
UNION ALL
SELECT 4 AS id
) ids
LEFT JOIN
suburbs s
ON s.suburb_id = ids.id
GROUP BY
id
or this:
SELECT id,
(
SELECT COUNT(*)
FROM suburb
WHERE suburb_id = id
)
FROM (
SELECT 1 AS id
UNION ALL
SELECT 2 AS id
UNION ALL
SELECT 3 AS id
UNION ALL
SELECT 4 AS id
) ids
This article compares performance of the two approaches:
Aggregates: subqueries vs. GROUP BY
, though it does not matter much in your case, as you are querying only 4 records.
Query:
select case
when total is null then 0
else total
end as total_with_zeroes,
suburb_id
from (SELECT COUNT(suburb_id) AS total, suburb_id
FROM suburbs
where suburb_id IN (1,2,3,4)
GROUP BY suburb_id) as dt
#geofftnz's solution works great if all conditions are simple like in this case. But I just had to solve a similar problem to generate a report where each column in the report is a different query. When you need to combine results from several select statements, then something like this might work.
You may have to programmatically create this query. Using left joins allows the query to return rows even if there are no matches to suburb_id with a given id. If your db supports it (which most do), you can use IFNULL to replace null with 0:
select IFNULL(a.count,0), IFNULL(b.count,0), IFNULL(c.count,0), IFNULL(d.count,0)
from (select count(suburb_id) as count from suburbs where id=1 group by suburb_id) a,
left join (select count(suburb_id) as count from suburbs where id=2 group by suburb_id) b on a.suburb_id=b.suburb_id
left join (select count(suburb_id) as count from suburbs where id=3 group by suburb_id) c on a.suburb_id=c.suburb_id
left join (select count(suburb_id) as count from suburbs where id=4 group by suburb_id) d on a.suburb_id=d.suburb_id;
The nice thing about this is that (if needed) each "left join" can use slightly different (possibly fairly complex) query.
Disclaimer: for large data sets, this type of query might have not perform very well (I don't write enough sql to know without investigating further), but at least it should give useful results ;-)