I have this SELECT query:
SELECT Auctions.ID, Users.Balance, Users.FreeBids,
COUNT(CASE WHEN Bids.Burned=0 AND Auctions.Closed=0 THEN 1 END) AS 'ActiveBids',
COUNT(CASE WHEN Bids.Burned=1 AND Auctions.Closed=0 THEN 1 END) AS 'BurnedBids'
FROM (Users INNER JOIN Bids ON Users.ID=Bids.BidderID)
INNER JOIN Auctions
ON Bids.AuctionID=Auctions.ID
WHERE Users.ID=#UserID
GROUP BY Users.Balance, Users.FreeBids, Auctions.ID
My problam is that it returns no rows if the UserID cant be found on the Bids table.
I know it's something that has to do with my
(Users INNER JOIN Bids ON Users.ID=Bids.BidderID)
But i dont know how to make it return even if the user is no on the Bids table.
You're doing an INNER JOIN, which only returns rows if there are results on both sides of the join. To get what you want, change your WHERE clause like this:
Users LEFT JOIN Bids ON Users.ID=Bids.BidderID
You may also have to change your SELECT statement to handle Bids.Burned being NULL.
If you want to return rows even if there's no matching Auction, then you'll have to make some deeper changes to your query.
My problam is that it returns no rows if the UserID cant be found on the Bids table.
Then INNER JOIN Bids/Auctions should probably be left outer joins. The way you've written it, you're filtering users so that only those in bids and auctions appear.
Left join is the simple answer, but if you're worried about performance I'd consider re-writing it a little bit. For one thing, the order of the columns in the group by matters to performance (although it often doesn't change the results). Generally, you want to group by a column that's indexed first.
Also, it's possible to re-write this query to only have one group by, which will probably speed things up.
Try this out:
with UserBids as (
select
a.ID
, b.BidderID
, ActiveBids = count(case when b.Burned = 0 then 1 end)
, BurnedBids = count(case when b.Burned = 0 then 1 end)
from Bids b
join Auctions a
on a.ID = b.AuctionID
where a.Closed = 0
group by b.BidderID, a.AuctionID
)
select
b.ID
, u.Balance
, u.FreeBids
, b.ActiveBids
, b.BurnedBids
from Users u
left join UserBids b
on b.BidderID = u.ID
where u.ID = #UserID;
If you're not familiar with the with UserBids as..., it's called a CTE (common table expression), and is basically a way to make a one-time use view, and a nice way to structure your queries.
Related
How I can add two fields that belong to an inner join?
I have this code:
select
SUM(ACT.NumberOfPlants ) AS NumberOfPlants,
SUM(ACT.NumOfJornales) AS NumberOfJornals
FROM dbo.AGRMastPlanPerformance MPR (NOLOCK)
INNER JOIN GENRegion GR ON (GR.intGENRegionKey = MPR.intGENRegionLink )
INNER JOIN AGRDetPlanPerformance DPR (NOLOCK) ON
(DPR.intAGRMastPlanPerformanceLink =
MPR.intAGRMastPlanPerformanceKey)
INNER JOIN vwGENPredios P (NOLOCK) ON ( DPR.intGENPredioLink =
P.intGENPredioKey )
INNER JOIN AGRSubActivity SA (NOLOCK) ON (SA.intAGRSubActivityKey =
DPR.intAGRSubActivityLink)
LEFT JOIN (SELECT RA.intGENPredioLink, AR.intAGRActividadLink,
AR.intAGRSubActividadLink, SUM(AR.decNoPlantas) AS
intPlantasTrabajads, SUM(AR.decNoPersonas) AS NumOfJornales,
SUM(AR.decNoPlants) AS NumberOfPlants
FROM AGRRecordActivity RA WITH (NOLOCK)
INNER JOIN AGRActividadRealizada AR WITH (NOLOCK) ON
(AR.intAGRRegistroActividadLink = RA.intAGRRegistroActividadKey AND
AR.bitActivo = 1)
INNER JOIN AGRSubActividad SA (NOLOCK) ON (SA.intAGRSubActividadKey
= AR.intAGRSubActividadLink AND SA.bitEnabled = 1)
WHERE RA.bitActive = 1 AND
AR.bitActive = 1 AND
RA.intAGRTractorsCrewsLink IN(2)
GROUP BY RA.intGENPredioLink,
AR.decNoPersons,
AR.decNoPlants,
AR.intAGRAActivityLink,
AR.intAGRSubActividadLink) ACT ON (ACT.intGENPredioLink IN(
DPR.intGENPredioLink) AND
ACT.intAGRAActivityLink IN( DPR.intAGRAActivityLink) AND
ACT.intAGRSubActivityLink IN( DPR.intAGRSubActivityLink))
WHERE
MPR.intAGRMastPlanPerformanceKey IN(4) AND
DPR.intAGRSubActivityLink IN( 1153)
GROUP BY
P.vchRegion,
ACT.NumberOfFloors,
ACT.NumOfJournals
ORDER BY ACT.NumberOfFloors DESC
However, it does not perform the complete sum. It only retrieves all the values of the columns and adds them 1 by 1, instead of doing the complete sum of the whole column.
For example, the query returns these results:
What I expect is the final sums. In NumberOfPlants the result of the sum would be 163,237 and of NumberJornales would be 61.
How can I do this?
First of all the (nolock) hints are probably not accomplishing the benefit you hope for. It's not an automatic "go faster" option, and if such an option existed you can be sure it would be already enabled. It can help in some situations, but the way it works allows the possibility of reading stale data, and the situations where it's likely to make any improvement are the same situations where risk for stale data is the highest.
That out of the way, with that much code in the question we're better served with a general explanation and solution for you to adapt.
The issue here is GROUP BY. When you use a GROUP BY in SQL, you're telling the database you want to see separate results per group for any aggregate functions like SUM() (and COUNT(), AVG(), MAX(), etc).
So if you have this:
SELECT Sum(ColumnB) As SumB
FROM [Table]
GROUP BY ColumnA
You will get a separate row per ColumnA group, even though it's not in the SELECT list.
If you don't really care about that, you can do one of two things:
Remove the GROUP BY If there are no grouped columns in the SELECT list, the GROUP BY clause is probably not accomplishing anything important.
Nest the query
If option 1 is somehow not possible (say, the original is actually a view) you could do this:
SELECT SUM(SumB)
FROM (
SELECT Sum(ColumnB) As SumB
FROM [Table]
GROUP BY ColumnA
) t
Note in both cases any JOIN is irrelevant to the issue.
Pretty basic SQL uses, I usually do some basic joins, and then pull data into Sheets to pivot or filter it to get what I want, but know I can do it quicker all in SQL.
For this query, I want to only return data if the c2.id count is greater than 0. I tried writing a subquery in the where clause, but feels like I need to group by task_id for this to be right...can someone help me understand what I should do and why?
select t.inserted_at::date, count (distinct c2.id), t.id, t.conversation_id
from tasks t
left join users u on u.id = t.creator_id
left join "comments" c2 on t.id = c2.task_id
left join conversations c on c.id = t.conversation_id
where u.include_in_metrics = true
and c.type = 'PROJECT_FEED'
group by 1,3,4
order by t.inserted_at::date desc;
Just add this after the group by before order by
having count(distinct c2.id)>0
I have three tables:
articles(id,title,message)
comments(id,article_id,commentedUser_id,comment)
comment_likes(id, likedUser_id, comment_id, action_like, action_dislike)
I want to show comments.id, comments.commentedUser_id, comments.comment, ( Select count(action_like) where action_like="like") as likes and comment_id=comments.id where comments.article_id=article.id
Actually I want to count all action_likes that related to any comment. And show all all comments of articles.
action_likes having only two values null or like
SELECT c.id , c.CommentedUser_id , c.comment , (cl.COUNT(action_like) WHERE action_like='like' AND comment_id='c.id') as likes
FROM comment_likes as cl
LEFT JOIN comments as c ON c.id=cl.comment_id
WHERE c.article_id=article.id
It shows nothing, I know I'm doing wrong way, that was just that I want say
I guess you are looking for something like below. This will return Article/Comment wise LIKE count.
SELECT
a.id article_id,
c.id comment_id,
c.CommentedUser_id ,
c.comment ,
COUNT (CASE WHEN action_like='like' THEN 1 ELSE NULL END) as likes
FROM article a
INNER JOIN comments C ON a.id = c.article_id
LEFT JOIN comment_likes as cl ON c.id=cl.comment_id
GROUP BY a.id,c.id , c.CommentedUser_id , c.comment
IF you need results for specific Article, you can add WHERE clause before the GROUP BY section like - WHERE a.id = N
I would recommend a correlated subquery for this:
SELECT a.id as article_id, c.id as comment_id,
c.CommentedUser_id, c.comment,
(SELECT COUNT(*)
FROM comment_likes cl
WHERE cl.comment_id = c.id AND
cl.action_like = 'like'
) as num_likes
FROM article a INNER JOIN
comments c
ON a.id = c.article_id;
This is a case where a correlated subquery often has noticeably better performance than an outer aggregation, particularly with the right index. The index you want is on comment_likes(comment_id, action_like).
Why is the performance better? Most databases will implement the group by by sorting the data. Sorting is an expensive operation that grows super-linearly -- that is, twice as much data takes more than twice as long to sort.
The correlated subquery breaks the problem down into smaller pieces. In fact, no sorting should be necessary -- just scanning the index and counting the matching rows.
I have the following query:
SELECT UserId, (
0.099 *
(
CASE WHEN
(SELECT AcceleratedProfitPercentage FROM CustomGroups cg
INNER JOIN UserCustomGroups ucg ON ucg.CustomGroupId = cg.Id
WHERE Packs.UserCustomGroupId = ucg.Id)
IS NOT NULL THEN
((SELECT AcceleratedProfitPercentage FROM CustomGroups cg
INNER JOIN UserCustomGroups ucg ON ucg.CustomGroupId = cg.Id
WHERE Packs.UserCustomGroupId = ucg.Id)*1.0) / (100*1.0)
ELSE 1
END
)
)
As amount
FROM Packs WHERE Id IN (
SELECT ap.Id FROM Packs ap JOIN Users u ON ap.UserId = u.UserId
WHERE ap.MoneyToReturn > ap.MoneyReturned AND
u.Mass LIKE '1%');
which is producing correct output. However I have no idea how to aggregate it properly. I tried to use standard GROUP BY but I get the error (Column 'Packs.UserCustomGroupId' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY claus). Any ideas? Here is the output I currently get:
I want to aggregate it by UserId. Thanks in advance.
The option that involves the least query-rewriting is to drop your existing query into a CTE or temp table, like so:
; with CTE as (MyQueryHere)
Select UserID, sum(amount)
from CTE
Group by UserID
Wow that is one crazy query you've got going on there.
Try this:
SELECT UserId,
0.099 * SUM(t.Amount) AS [Amount SUM]
FROM Packs P
JOIN Users U
ON P.UserID = U.UserID
LEFT OUTER JOIN UserCustomGroups UCG
ON P.UserCustomGroupID = UCG.ID
LEFT OUTER JOIN CustomGroups CG
ON UCG.CustomGroupID = CG.ID
CROSS APPLY
(
SELECT CASE WHEN CG.ID IS NULL
THEN 1
ELSE CG.AcceleratedProfitPercentage / 100
END AS [Amount]
) t
WHERE P.MoneyToReturn > P.MoneyReturned
AND U.Mass LIKE '1%'
GROUP BY UserID
First, multiplying any number by 1 is pretty pointless, yet I see it twice in your original post. I'm not sure what led to that, but it's unnecessary.
Also, using CROSS APPLY will eliminate the need for you to repeat your subquery. Granted, it's slower (since it'll run on every row returned), but I think it makes sense in this case...Using left outer joins instead of CASE - SELECT - IS NULL makes your query much more efficient and much more readable.
Next, it appears that you are attempting to SUM percentages. Not sure what kind of data you're looking to return, but perhaps AVG would be more appropriate? I can't think of any practical reason why you would be looking to do that.
Lastly, APH's answer will most certainly work (assuming your original query works), but given the obfuscation and inefficiency of your query, I would definitely rewrite it.
Please let me know if you have any questions.
Hi and sorry if that's a stupud question but I am trying to get results from two different tables and since one of them might have zero records I am not sure how to proceed. Here is the query:
SELECT aid.*, T.ItemId, T.Total, T.Stack
FROM (SELECT ItemId, Stack, count(ItemId) as Total FROM auction_house WHERE Sale = 0 GROUP BY ItemId, Stack) as T, ahbot_item_data aid
WHERE T.ItemId = aid.ItemId
AND T.Stack = aid.Stack
Basically I want to get a list of items from the aid table, and the current count of those items in the ah table. But since the count might just be zero, it might not return that row. I want the row and the Total to be 0.
Thank you in advance ^^;;
Similar to what #Twelfth was saying, you want to have a left outer join, which always outputs data from the left table even if there is no matching data in the right table.
SELECT
aid.ItemId,
count(ah.ItemId) AS "Total",
aid.Stack
FROM
ahbot_item_data aid
LEFT OUTER JOIN auction_house ah
ON (aid.ItemID = ah.ItemID AND aid.Stack = ah.Stack)
GROUP BY
aid.ItemID, aid.Stack
You are using old syntax...I'm going to switch to join syntax (newer and more accepted...same effect, easier to read). What you want is an 'outer join', which will produce nulls where no record is found. I'll arrange the tables and we'll use a left outer join
SELECT aid.*, T.ItemId, T.Total, T.Stack
FROM ahbot_item_data aid left join (SELECT ItemId, Stack, count(ItemId) as Total FROM auction_house WHERE Sale = 0 GROUP BY ItemId, Stack) as T,
on T.ItemId = aid.ItemId
AND T.Stack = aid.Stack
I'm not entirely sure on the syntax anymore...but it's also possible to use != to do this outer join in the syntax you've used (where aid.itemID != t.itemID I think?)