i am retrieving data from three tables for my requirement so i wrote the following query
i was getting correct result but the problem is records are repeated whats the problem in
that query. i am binding result of query to grid view control. please help me
SELECT DISTINCT (tc.coursename), ur.username, uc. DATE, 'Paid' AS Status
FROM tblcourse tc, tblusereg ur, dbo.UserCourse uc
WHERE tc.courseid IN (SELECT ur1.courseid
FROM dbo.UserCourse ur1
WHERE ur1.userid = #userid)
AND ur.userid = #userid
AND uc. DATE IS NOT NULL
AND ur.course - id = uc.course - id
There is no JOIN between tblcourse tc,tblusereg ur. So you get a cross join despite the IN (which is actually a JOIN)
DISTINCT works on the whole row too: not one column.
Note: you mention dbo.UserCourse twice but use different column names courseid and [course-id]
Rewritten with JOINs.
select distinct
tc.coursename, ur.username, uc.[date], 'Paid' as [Status]
from
dbo.tblcourse tc
JOIN
dbo.tblusereg ur ON tc.courseid = ur.[course-id]
JOIN
dbo.UserCourse uc ON ur.[course-id] = uc.[course-id]
where
ur.userid=#userid
and
uc.[date] is not null
This may fix your problem...
Change that first part of your query
select distinct (tc.coursename),
TO
select distinct tc.coursename,
to make all the columns distinct not just tc.coursename
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.
i have following sql in java project:
select distinct * from drivers inner join licenses on drivers.user_id=licenses.issuer_id
inner join users on drivers.user_id=users.id
where (licenses.state='ISSUED' or drivers.status='WAITING')
and users.is_deleted=false
And result i database looks like this:
And i would like to get only one result instead of two duplicated results.
How can i do that?
Solution 1 - That's Because one of data has duplicate value write distinct keyword with only column you want like this
Select distinct id, distinct creation_date, distinct modification_date from
YourTable
Solution 2 - apply distinct only on ID and once you get id you can get all data using in query
select * from yourtable where id in (select distinct id from drivers inner join
licenses
on drivers.user_id=licenses.issuer_id
inner join users on drivers.user_id=users.id
where (licenses.state='ISSUED' or drivers.status='WAITING')
and users.is_deleted=false )
Enum fields name on select, using COALESCE for fields which value is null.
usually you dont query distinct with * (all columns), because it means if one column has the same value but the rest isn't, it will be treated as a different rows. so you have to distinct only the column you want to, then get the data
I suspect that you want left joins like this:
select *
from users u left join
drivers d
on d.user_id = u.id and d.status = 'WAITING' left join
licenses l
on d.user_id = l.issuer_id and l.state = 'ISSUED'
where u.is_deleted = false and
(d.user_id is not null or l.issuer_id is not null);
I am working on the the report which get my nerves because I cannot do simple query to exclude users which does not exists in order table. This supposed to be easy query but the I need to join two tables.
Select User_ID, FirstName, Surname, UserType
FROM user
Left Join Order. ID ON Order.User_Id = User.User_ID
User_ID = Order_Ref WHERE Oder_Ref IS NULL
Where UserType ='Super'
Now I come across report where Order.User_ID is has varchar data type and unfortunately, I cannot create query that extract data properly. Properly because I tried use isNumeric(Order.User_Id), use regular expressions, WHERE Order.User_Id not like '%[^0-9]%', and Order.User_Id != '', use not exists statements. None of the above helped really.
At the moment I have end up with:
Select User.User_Id, isNumeric(Order.Order_Id)
FROM User Left Join
Order
ON User.User_Id = Order.User_Id
WHERE (Order.Order_Id IS NULL AND ISNUMERIC(Order.Order_Id) = 1 AND User.UserType = 'Super')
This query is compiled without any problems but it does not return anything.
Could you please give me a hint what would be approach to do it.
I really appreciate for your help.
First - if user_id is the same thing in your [user] and [order] tables then they should have the same data type, referential integrity should be enforced (e.g. via PK/FK relationship). I understand that this may not be your call however.
Next - ISNUMERIC does not do what people think it does. To understand what I'm saying run these queries and try to figure out what ISNUMERIC really does:
select ISNUMERIC('$'), ISNUMERIC($), ISNUMERIC('$.,'), ISNUMERIC('$,'), ISNUMERIC('10,,0'), ISNUMERIC('');
select ISNUMERIC(''), cast('' as int), ''+2;
--select ISNUMERIC('$'), '$'+2; -- this errors, but is still worth runnning
For what you are describing I would use a subquery and do your filtering before the join like this:
Note that I included a couple ways your could check for non-numeric characters.
select [User].User_Id, isNumeric([Order].Order_Id)
from [User]
Left Join
(
select [order].Order_Id
from [order]
where [order].Order_Id NOT like '%[^0-9]%' -- contains only numbers
--where patindex('%[^0-9]%', [order].Order_Id) = 0
--where try_cast([order].Order_Id as int) is not null -- SQL Server 2012+
and [User].UserType = 'Super'
) [order]
on [User].User_Id = [order].User_Id
Change
Left Join Order ON Order.User_Id = User.User_ID
to
inner Join Order ON Order.User_Id = User.User_ID
That will restrict the results to users with orders. Your posted code has syntax errors you have to fix.
In my mind these 2 sql statements are equivalent.
My understanding is:
the first one i am pulling all rows from tmpPerson and filtering where they do not have an equivalent person id. This query returns 211 records.
The second one says give me all tmpPersons whose id isnt in person. this returns null.
Obviously they are not equivalent or theyd have the same results. so what am i missing? thanks
select p.id, bp.id
From person p
right join(
select distinct id
from tmpPerson
) bp
on p.id= bp.id
where p.id is null
select id
from tmpPerson
where id not in (select id from person)
I pulled some ids from the first result set and found no matching records for them in Person so im guessing the first one is accurate but im still surprised they're different
I much prefer left joins to right joins, so let's write the first query as:
select p.id, bp.id
From (select distinct id
from tmpPerson
) bp left join
person p
on p.id = bp.id
where p.id is null;
(The preference is because the result set keeps all the rows in the first table rather than the last table. When reading the from clause, I immediately know what the first table is.)
The second is:
select id
from tmpPerson
where id not in (select id from person);
These are not equivalent for two reasons. The most likely reason in your case is that you have duplicate ids in tmpPerson. The first version removes the duplicates. The second doesn't. This is easily fixed by putting distincts in the right place.
The more subtle reason has to do with the semantics of not in. If any person.id has a NULL value, then all rows will be filtered out. I don't think that is the case with your query, but it is a difference.
I strongly recommend using not exists instead of not in for the reason just described:
select tp.id
from tmpPerson tp
where not exists (select 1 from person p where p.id = tp.id);
select id
from tmpPerson
where id not in (select id from person)
If there is a null id in tmp person then they will not be captured in this query. But in your first query they will be captured. So using an isnull will be resolve the issue
where isnull(id, 'N') not in (select id from person)
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.