Linq join and tenary query - entity-framework

I am trying to do a join with a tenary expression as shown following.
The "AddedSince" is calculated in the model from the date the customer was added, The period is a dynamic and it is picked from the url query parameter.
What I am trying to achieve is to check if the person has been added at a shorter period than the period requested if so use the AddedSince value. There are other joins and all work well except this one I am not sure am doing it right. The error is that "int does not contain a definition for CustomerId"
int period =6;
var query =( from bk in customers.....
join cu in db.Customers.Where(a=>a.MemberOk).Select(a => a.AddedSince < period ? a.AddedSince: period)
on bk.CustomerId equals cu.CustomerId into cuspd )
can I use a tenery operation in this way at all with linq? if yes how do I do this. Thanks

You can use the tenary operator, but you can not add the select in the middle of join.
Instead, you can do the join as normal and then perform the select, ie
int period =6;
var query = (from bk in customers.....
join cu in db.Customers on bk.CustomerId equals cu.CustomerId
where cu.MemberOk
select a.AddedSince < period ? a.AddedSince: period
);
The .Where(a=>a.MemberOk) section could be left where you have it, but I have moved it to avoid mixing query and lamba styles.

Related

SQL Server: How to customize one column in Order By clause out of many other columns in order by

I have store procedure which return data fine and it was developed by some one else who now not in touch.
Output now looks like
Here i am attaching a part of the query which return data.
SET #sql = '
Select XX.*,'''' scale,Isnull(AllowComma,''FALSE'') AllowComma,Isnull(AllowedDecimalPlace,''0'') AllowedDecimalPlace,
Isnull(AllowPercentageSign,''FALSE'') AllowPercentageSign,Isnull(CurrencySign,'''') CurrencySign,Isnull(BM_Denominator,'''') BM_Denominator
From
(
---- Broker Detail
Select AA.Section,AA.LineItem,Csm.DisplayInCSM ,AA.BrokerCode Broker,AA.BrokerName,'''' BM_Element,'''' BM_Code,AA.Ord,AA.[Revise Date],AA.LineItemId,
Csm.ID,[FontName],[FontStyle],[FontSize],[UnderLine],[BGColor],[FGColor],[Indent],[Box],[HeadingSubHeading],
'+#PeriodCols+','+#PeriodColsComment +',LineItem_Comment,BrokerName_Comment,Date_Comment
From tblCSM_ModelDetails Csm LEFT OUTER JOIN (
Select b.*,L.ID LineItemId
From #TmpAll_Broker_LI b
INNER JOIN TblLineItemTemplate L ON TickerID='''+#TickerID+''' AND b.LineItem= L.LineItem
) AA ON Csm.LineItemId=AA.LineItemId
WHERE Csm.CSM_ID='+TRIM(CONVERT(CHAR(10),#CSM_Id))+' AND Csm.BMID=0 AND Type !=''SHEET''
UNION
----- Consensus
Select Section, b.LineItem,DisplayInCSM, '''' Broker,'''' BrokerName,'''' BM_Element,'''' BM_Code, Ord,'''' [Revise Date],L.ID LineItemID,
Csm.ID,[FontName],[FontStyle],[FontSize],[UnderLine],[BGColor],[FGColor],[Indent],[Box],[HeadingSubHeading],
'+#PeriodCols+','+#PeriodColsComment +',LineItem_Comment,BrokerName_Comment,Date_Comment
From #TmpZacksCons b
INNER JOIN TblLineItemTemplate L ON TickerID='''+#TickerID+''' AND b.LineItem= L.LineItem
INNER JOIN tblCSM_ModelDetails Csm ON Csm.LineItemID=L.ID
WHERE Csm.CSM_ID='+TRIM(CONVERT(CHAR(10),#CSM_Id))+' AND Csm.BMID=0
---- Blue Metrics
UNION
Select Section, b.LineItem,DisplayInCSM,'''' Broker,'''' BrokerName,BM_Element,Code BM_Code, Ord,'''' [Revise Date],L.ID LineItemID,
Csm.ID,[FontName],[FontStyle],[FontSize],[UnderLine],[BGColor],[FGColor],[Indent],[Box],[HeadingSubHeading],
'+#PeriodCols+','+#PeriodColsComment +',LineItem_Comment,BrokerName_Comment,Date_Comment
From #TmpBM b
INNER JOIN TblLineItemTemplate L ON TickerID='''+#TickerID+''' AND b.LineItem= L.LineItem
INNER JOIN tblCSM_ModelDetails Csm ON Csm.BMID=b.code AND Csm.LineItemID=L.ID
WHERE Csm.CSM_ID='+TRIM(CONVERT(CHAR(10),#CSM_Id))+'
AND Ord IS NOT NULL
) XX
Left Outer Join tblLiConfig ZZ
On XX.Section=ZZ.Section And XX.LineItem=ZZ.LI And ZZ.Ticker='''+#Ticker+'''
Order by ID,Ord,BM_Code,LineItem,BrokerName'
Now broker Name is not coming as alphabetical order and it is the issue.
see this line at the bottom Order by ID,Ord,BM_Code,LineItem,BrokerName
When i try to change this order by like Order by ID,Ord,BM_Code,LineItem,BrokerName IN (SELECT BrokerName FROM #Brokers ORDER BY BrokerName ASC)' then getting error like clause is invalid in views, inline functions, derived tables, subqueries, and common table expressions, unless TOP, OFFSET or FOR XML is also specified.
in my order by there are many columns and data is getting order by that way but i need to show broker name in alphabetical order but i am not being able. so please some one guide me how can i customize this sql.
Here i have not attached my full store procedure code because it is very large. looking for suggestion & help. Thanks
Short version
The ORDER BY is doing what is expected - ordering first by ID, then Ord, then BM_Code, then LineItem, then BrokerName.
Within ID 76187, the next field to order by is Ord - which it sorts from 30911, to 31097.
If it previously ordered by BrokerName, it was only by chance - or that Ord was ordered the same way as BrokerName.
My initial suggestion is to re-order your sort e.g., ORDER BY ID, BM_Code, LineItem, BrokerName, Ord
Longer explanation of issue
In SQL, underlying data is treated as a set and ordering doesn't matter.
For example, if you have a variable #x and you were testing IF #x IN (1,2,3,4,5) will produce the same result as IF #x in (5,4,3,2,1).
In your example, you're putting an ORDER BY into the sub-query you're checking with the IN e.g., ORDER BY ... BrokerName IN (SELECT BrokerName FROM #Brokers ORDER BY BrokerName ASC). The order of that sub-query isn't allowed, and wouldn't do anything anyway.
The only sort that matters (other than for a few things like TOP) is the final sort - when displaying the data.
That being said, even if you removed the ORDER BY in the sub-query, it wouldn't help you with your issue
The SQL is not likely to work anyway - ORDER BY needs a value - you may have needed to make it CASE WHEN BrokerName IN (...) THEN 0 ELSE 1 END
Which also won't help, as the issue is that Ord is sorted before BrokerName anyway.
UPDATE following comment
Fundamentally, the statement that provides the actual report is
SET #sql = '
Select XX.*,'''' scale,Isnull(AllowComma,''FALSE'') AllowComma,Isnull(AllowedDecimalPlace,''0'') AllowedDecimalPlace,
Isnull(AllowPercentageSign,''FALSE'') AllowPercentageSign,Isnull(CurrencySign,'''') CurrencySign,Isnull(BM_Denominator,'''') BM_Denominator
From (<a whole lot of calculations/cpode>) XX
Left Outer Join tblLiConfig ZZ
On XX.Section=ZZ.Section And XX.LineItem=ZZ.LI And ZZ.Ticker='''+#Ticker+'''
Order by ID,Ord,BM_Code,LineItem,BrokerName'
The last line on there provides the ordering of the data coming from this procedure.
To get a different order, you need to change the order of the fields shown - moving BrokerName more towards the start of the list, and Ord towards the end.
e.g.,
SET #sql = '
Select XX.*,'''' scale,Isnull(AllowComma,''FALSE'') AllowComma,Isnull(AllowedDecimalPlace,''0'') AllowedDecimalPlace,
Isnull(AllowPercentageSign,''FALSE'') AllowPercentageSign,Isnull(CurrencySign,'''') CurrencySign,Isnull(BM_Denominator,'''') BM_Denominator
From (<a whole lot of calculations/cpode>) XX
Left Outer Join tblLiConfig ZZ
On XX.Section=ZZ.Section And XX.LineItem=ZZ.LI And ZZ.Ticker='''+#Ticker+'''
Order by ID,BrokerName,BM_Code,LineItem,Ord'
The above probably sorts by BrokerName too early - but it's up to you to determine what you need.

SQLITE : Optimize ORDER BY Query

All,
I am iOS developer. Currently we have stored 2.5 lacks data in database. And we have implemented search functionality on that. Below is the query that we are using.
select CustomerMaster.CustomerName ,CustomerMaster.CustomerNumber,
CallActivityList.CallActivityID,CallActivityList.CustomerID,CallActivityList.UserID,
CallActivityList.ActivityType,CallActivityList.Objective,CallActivityList.Result,
CallActivityList.Comments,CallActivityList.CreatedDate,CallActivityList.UpdateDate,
CallActivityList.CallDate,CallActivityList.OrderID,CallActivityList.SalesPerson,
CallActivityList.GratisProduct,CallActivityList.CallActivityDeviceID,
CallActivityList.IsExported,CallActivityList.isDeleted,CallActivityList.TerritoryID,
CallActivityList.TerritoryName,CallActivityList.Hours,UserMaster.UserName,
(FirstName ||' '||LastName) as UserNameFull,UserMaster.TerritoryID as UserTerritory
from
CallActivityList
inner join CustomerMaster
ON CustomerMaster.DeviceCustomerID = CallActivityList.CustomerID
inner Join UserMaster
On UserMaster.UserID = CallActivityList.UserID
where
(CustomerMaster.CustomerName like '%T%' or
CustomerMaster.CustomerNumber like '%T%' or
CallActivityList.ActivityType like '%T%' or
CallActivityList.TerritoryName like '%T%' or
CallActivityList.SalesPerson like '%T%' )
and CallActivityList.IsExported!='2' and CallActivityList.isDeleted != '1'
order by
CustomerMaster.CustomerName
limit 50 offset 0
Without using 'order by' The query is returning result in 0.5 second. But when i am attaching 'order by', Time is increasing to 2 seconds.
I have tried indexing but it is not making any noticeable change. Any one please help. If we are not going through Query then how can we do it fast.
Thanks in advance.
This is due to the the limit. Without ORDER BY only 50 records have to be processed and any 50 will be returned. With ORDER BY all the records have to be processed in order to determine which ones are the first 50 (in order).
The problem is that the ORDER BY is performed on a joined table. Otherise you could apply the limit on the main table (I assume it is the CallActivityList) first and then join.
SELECT ...
FROM
(SELECT ... FROM CallActivityList ORDER BY ... LIMIT 50 OFFSET 0) AS CAL
INNER JOIN CustomerMaster ON ...
INNER JOIN UserMaster ON ...
ORDER BY ...
This would reduce the costs for joining the tables. If this is not possible, try at least to join CallActivityList with CustomerMaster. Apply the limit to those and finally join with UserMaster.
SELECT ...
FROM
(SELECT ...
FROM
CallActivityList
INNER JOIN CustomerMaster ON ...
ORDER BY CustomerMaster.CustomerName
LIMIT 50 OFFSET 0) AS ActCust
INNER JOIN UserMaster ON ...
ORDER BY ...
Also, in order to make the ordering unambiguous, I would include more columns into the order by, like call date and call id. Otherwise this could result in a inconsistent paging.

Tableau - Calculating average where date is less than value from another data source

I am trying to calculate the average of a column in Tableau, except the problem is I am trying to use a single date value (based on filter) from another data source to only calculate the average where the exam date is <= the filtered date value from the other source.
Note: Parameters will not work for me here, since new date values are being added constantly to the set.
I have tried many different approaches, but the simplest was trying to use a calculated field that pulls in the filtered exam date from the other data source.
It successfully can pull the filtered date, but the formula does not work as expected. 2 versions of the calculation are below:
IF DATE(ATTR([Exam Date])) <= DATE(ATTR([Averages (Tableau Test Scores)].[Updated])) THEN AVG([Raw Score]) END
IF DATEDIFF('day', DATE(ATTR([Exam Date])), DATE(ATTR([Averages (Tableau Test Scores)].[Updated]))) > 1 THEN AVG([Raw Score]) END
Basically, I am looking for the equivalent of this in SQL Server:
SELECT AVG([Raw Score]) WHERE ExamDate <= (Filtered Exam Date)
Below a workbook that shows an example of what I am trying to accomplish. Currently it returns all blanks, likely due to the many-to-one comparison I am trying to use in my calculation.
Any feedback is greatly appreciated!
Tableau Test Exam Workbook
I was able to solve this by using Custom SQL to join the tables together and calculate the average based on my conditions, to get the column results I wanted.
Would still be great to have this ability directly in Tableau, but whatever gets the job done.
Edit:
SELECT
[AcademicYear]
,[Discipline]
--Get the number of student takers
,COUNT([Id]) AS [Students (N)]
--Get the average of the Raw Score
,CAST(AVG(RawScore) AS DECIMAL(10,2)) AS [School Mean]
--Get the number of failures based on an "adjusted score" column
,COUNT([AdjustedScore] < 70 THEN 1 END) AS [School Failures]
--This is the column used as the cutoff point for including scores
,[Average_Update].[Updated]
FROM [dbo].[Average] [Average]
FULL OUTER JOIN [dbo].[Average_Update] [Average_Update] ON ([Average_Update].[Id] = [Average].UpdateDateId)
--The meat of joining data for accurate calculations
FULL OUTER JOIN (
SELECT DISTINCT S.[Id], S.[LastName], S.[FirstName], S.[ExamDate], S.[RawScoreStandard], S.[RawScorePercent], S.[AdjustedScore], S.[Subject], P.[Id] AS PeriodId
FROM [StudentScore] S
FULL OUTER JOIN
(
--Get only the 1st attempt
SELECT DISTINCT [NBOMEId], S2.[Subject], MIN([ExamDate]) AS ExamDate
FROM [StudentScore] S2
GROUP BY [NBOMEId],S2.[Subject]
) B
ON S.[NBOMEId] = B.[NBOMEId] AND S.[Subject] = B.[Subject] AND S.[ExamDate] = B.[ExamDate]
--Group in "Exam Periods" based on the list of periods w/ start & end dates in another table.
FULL OUTER JOIN [ExamPeriod] P
ON S.[ExamDate] = P.PeriodStart AND S.[ExamDate] <= P.PeriodEnd
WHERE S.[Subject] = B.[Subject]
GROUP BY P.[Id], S.[Subject], S.[ExamDate], S.[RawScoreStandard], S.[RawScorePercent], S.[AdjustedScore], S.[NBOMEId], S.[NBOMELastName], S.[NBOMEFirstName], S.[SecondYrTake]) [StudentScore]
ON
([StudentScore].PeriodId = [Average_Update].ExamPeriodId
AND [StudentScore].Subject = [Average].Subject
AND [StudentScore].[ExamDate] <= [Average_Update].[Updated])
--End meat
--Joins to pull in relevant data for normalized tables
FULL OUTER JOIN [dbo].[Student] [Student] ON ([StudentScore].[NBOMEId] = [Student].[NBOMEId])
INNER JOIN [dbo].[ExamPeriod] [ExamPeriod] ON ([Average_Update].ExamPeriodId = [ExamPeriod].[Id])
INNER JOIN [dbo].[AcademicYear] [AcademicYear] ON ([ExamPeriod].[AcademicYearId] = [AcademicYear].[Id])
--This will pull only the latest update entry for every academic year.
WHERE [Updated] IN (
SELECT DISTINCT MAX([Updated]) AS MaxDate
FROM [Average_Update]
GROUP BY[ExamPeriodId])
GROUP BY [AcademicYear].[AcademicYearText], [Average].[Subject], [Average_Update].[Updated],
ORDER BY [AcademicYear].[AcademicYearText], [Average_Update].[Updated], [Average].[Subject]
I couldn't download your file to test with your data, but try reversing the order of taking the average ie
average(IF DATE(ATTR([Exam Date])) <= DATE(ATTR([Averages (Tableau Test Scores)].[Updated]) then [Raw Score]) END)
as written, I believe you'll be averaging the data before returning it from the if statement, whereas you want to return the data, then average it.

Error in update query

I have two entities STOCK(name,amount) and PC_SYSTEMS(name,c_name), and i wish to update the components needed to create the PC_system "Alienware", therefore i want it to subtract 1 from the amount of the components, needed to create the alienware system, in Stock.
Here's my query:
"UPDATE stock SET amount=amount-1 WHERE name = ( SELECT p.c_name FROM pc_systems p WHERE p.name='Alienware');"
I get a weird error that says:
" more than one row returned by a subquery used as an expression"
Would be happy if someone could help.
Edit:
I SOLVED this by putting an "IN" in my query instead of "=". Final code:
UPDATE stock SET amount=amount-1 WHERE name IN ( SELECT p.c_name FROM pc_systems p WHERE p.name='Alienware');
What it means is this SQL returns more than 1 row. Make it so it returns exactly 1 row only.
SELECT p.c_name FROM pc_systems p WHERE p.name='Alienware'
Since your subquery is returning more than one record you cannot use that syntax. try something like this:
UPDATE S
SET S.amount=S.amount-1
FROM Stock S
INNER JOIN pc_systems p
ON S.name = p.c_name
WHERE p.name='Alienware'
or try this:
update stock
set s.amount=s.amount-1
from stock s
inner join pc_systems p on S.name = p.c_name
where p.name='Alienware'

Convert SQL to LINQ, nested select, top, "distinct" using group by and multiple order bys

I have the following SQL query, which I'm struggling to convert to LINQ.
Purpose: Get the top 10 coupons from the table, ordered by the date they expire (i.e. list the ones that are about to expire first) and then randomly choosing one of those for publication.
Notes: Because of the way the database is structured, there maybe duplicate Codes in the Coupon table. Therefore, I am using a GROUP BY to enforce distinction, because I can't use DISTINCT in the sub select query (which I think is correct). The SQL query works.
SELECT TOP 1
c1.*
FROM
Coupon c1
WHERE
Code IN (
SELECT TOP 10
c2.Code
FROM
Coupon c2
WHERE
c2.Published = 0
GROUP BY
c2.Code,
c2.Expires
ORDER BY
c2.Expires
)
ORDER BY NEWID()
Update:
This is as close as I have got, but in two queries:
var result1 = (from c in Coupons
where c.Published == false
orderby c.Expires
group c by new { c.Code, c.Expires } into coupon
select coupon.FirstOrDefault()).Take(10);
var result2 = (from c in result1
orderby Guid.NewGuid()
select c).Take(1);
Here's one possible way:
from c in Coupons
from cs in
((from c in coupons
where c.published == false
select c).Distinct()
).Take(10)
where cs.ID == c.ID
select c
Keep in mind that LINQ creates a strongly-typed data set, so an IN statement has no general equivalent. I understand trying to keep the SQL tight, but LINQ may not be the best answer for this. If you are using MS SQL Server (not SQL Server Compact) you might want to consider doing this as a Stored Procedure.
Using MercurioJ's slightly buggy response, in combination with another SO suggested random row solution my solution was:
var result3 = (from c in _dataContext.Coupons
from cs in
((from c1 in _dataContext.Coupons
where
c1.IsPublished == false
select c1).Distinct()
).Take(10)
where cs.CouponId == c.CouponId
orderby _dataContext.NewId()
select c).Take(1);