I want to get all AddOns(without duplication) with the combination HealthInsuranceQuotationMemberPlanBenefit data. AddOnsID at HealthInsuranceQuotationMemberPlanBenefit is the primary key of AddOns table.
(from mq in context.HealthInsuranceQuotationMember
join mp in context.HealthInsuranceQuotationMemberPlanBenefit on mq.ID equals mp.HealthInsuranceQuotationMemberID
join ao in context.AddOns on mp.AddOnsID equals ao.ID
where mq.HealthInsurancePlanID == 1 && ao.Category != 2
group mp by new { ao.ID, ao.Name, ao.Category } into g
let fmp = g.First()
select new HealthInsurancePlanAddOnsViewModel
{
ID = g.Key.ID,
Name = g.Key.Name,
CategoryID = (int)g.Key.Category,
Category = g.Key.Category.ToDescription(),
Value = fmp.Description,
Premium = fmp.Premium,
})
.ToList();
When I am trying to get the first item of HealthInsuranceQuotationMemberPlanBenefit using fmp = g.First() it raising following error:
Processing of the LINQ expression '(GroupByShaperExpression:
KeySelector: new {
ID = (a.ID),
Name = (a.Name),
Category = (a.Category)
},
ElementSelector:(EntityShaperExpression:
EntityType: HealthInsuranceQuotationMemberPlanBenefit
ValueBufferExpression:
(ProjectionBindingExpression: EmptyProjectionMember)
IsNullable: False
)
)' by 'RelationalProjectionBindingExpressionVisitor' failed. This may indicate either a bug or a limitation in EF Core. See https://go.microsoft.com/fwlink/?linkid=2101433 for more detailed information.
If I remove the selection of HealthInsuranceQuotationMemberPlanBenefit(let fmp = g.First(), Value = fmp.Description, Premium = fmp.Premium) data, it is working.
I investigate the occurred because of g.First()
Also, how can I solve & improve this query?
Related
var abc1 = from dlist in db.DebtorTransactions.ToList()
join war in db.Warranties on dlist.ProductID equals war.Id
join ag in db.Agents on war.fldAgentID equals ag.pkfAgentID
join sr in db.SalesReps on war.fldSrId equals sr.pkfSrID
where dlist.TransTypeID == 1
select new
{
dlist.Amount,
dlist.TransTypeID,
name = ag.Name,
ag.pkfAgentID,
sr.pkfSrID,
salesnam = sr.Name
} into objabc
group objabc by new
{
objabc.TransTypeID,
objabc.name,
objabc.salesnam,
objabc.Amount
};
var amt1 = abc1.Sum(x => x.Key.Amount);
var abc2 = from dlist in db.DebtorTransactions.ToList()
join cjt in db.CarJackaTrackas on dlist.ProductID equals cjt.pkfCjtID
join ag in db.Agents on cjt.AgentID equals ag.pkfAgentID
join sr in db.SalesReps on cjt.SalesRepId equals sr.pkfSrID
where dlist.TransTypeID == 0
select new
{
dlist.Amount,
dlist.TransTypeID,
name = ag.Name,
ag.pkfAgentID,
sr.pkfSrID,
enter code here` salesnam = sr.Name
} into objabc
group objabc by new
{
objabc.TransTypeID,
objabc.name,
objabc.salesnam,
objabc.Amount
};
var amt2 = abc1.Sum(x => x.Key.Amount);
//var result1=
return View();
i am new to linq, this query is working but i need to get the sum of Amount where dlist.TransTypeID == 0 and where dlist.TransTypeID == 1 by just single query. may anybody help me? thanks in advance
Here's a trimmed down example of how you can do it. You can add the joins if they are necessary, but I'm not clear on why you need some of the extra join values.
var transTypeAmountSums = (from dlist in db.DebtorTransactions
group dlist by dlist.TransTypeId into g
where g.Key == 0 || g.Key == 1
select new
{
TransTypeId = g.Key,
AmountSum = g.Sum(d => d.Amount)
}).ToDictionary(k => k.TransTypeId, v => v.AmountSum);
int transTypeZeroSum = transTypeAmountSums[0];
int transTypeOneSum = transTypeAmountSums[1];
A couple of things to note:
I removed ToList(). Unless you want to bring ALL DebtorTransactions into memory then run a Linq operation on those results, you'll want to leave that out and let SQL take care of the aggregation (it's much better at it than C#).
I grouped by dlist.TransTypeId only. You can still group by more fields if you need that, but it was unclear in the example why they were needed so I just made a simplified example.
I have the following LINQ query using EF5 and generic repository, unit of work patterns to a SQL Server 2008 db
var countriesArr = GetIdsFromDelimStr(countries);
var competitionsArr = GetIdsFromDelimStr(competitions);
var filterTeamName = string.Empty;
if (teamName != null)
{
filterTeamName = teamName.ToUpper();
}
using (var unitOfWork = new FootballUnitOfWork(ConnFooty))
{
// give us our selection of teams
var teams =
(from team in
unitOfWork.TeamRepository.Find()
where ((string.IsNullOrEmpty(filterTeamName) || team.Name.ToUpper().Contains(filterTeamName)) &&
(countriesArr.Contains(team.Venue.Country.Id) || countriesArr.Count() == 0))
select new
{
tId = team.Id
}).Distinct();
// give us our selection of contests
var conts = (
from cont in
unitOfWork.ContestRepository.Find(
c =>
((c.ContestType == ContestType.League && competitionsArr.Count() == 0) ||
(competitionsArr.Contains(c.Competition.Id) && competitionsArr.Count() == 0)))
select new
{
contId = cont.Id
}
).Distinct();
// get selection of home teams based on contest
var homecomps = (from fixt in unitOfWork.FixtureDetailsRepository.Find()
where
teams.Any(t => t.tId == fixt.HomeTeam.Id) &&
conts.Any(c => c.contId == fixt.Contest.Id)
select new
{
teamId = fixt.HomeTeam.Id,
teamName = fixt.HomeTeam.Name,
countryId = fixt.HomeTeam.Venue.Country.Id != null ? fixt.HomeTeam.Venue.Country.Id : 0,
countryName = fixt.HomeTeam.Venue.Country.Id != null ? fixt.HomeTeam.Venue.Country.Name : string.Empty,
compId = fixt.Contest.Competition.Id,
compDesc = fixt.Contest.Competition.Description
}).Distinct();
// get selection of away teams based on contest
var awaycomps = (from fixt in unitOfWork.FixtureDetailsRepository.Find()
where
teams.Any(t => t.tId == fixt.AwayTeam.Id) &&
conts.Any(c => c.contId == fixt.Contest.Id)
select new
{
teamId = fixt.AwayTeam.Id,
teamName = fixt.AwayTeam.Name,
countryId = fixt.AwayTeam.Venue.Country.Id != null ? fixt.AwayTeam.Venue.Country.Id : 0,
countryName = fixt.AwayTeam.Venue.Country.Id != null ? fixt.AwayTeam.Venue.Country.Name : string.Empty,
compId = fixt.Contest.Competition.Id,
compDesc = fixt.Contest.Competition.Description
}).Distinct();
// ensure that we return the max competition based on id for home teams
var homemax = (from t in homecomps
group t by t.teamId
into grp
let maxcomp = grp.Max(g => g.compId)
from g in grp
where g.compId == maxcomp
select g).Distinct();
// ensure that we return the max competition based on id for away teams
var awaymax = (from t in awaycomps
group t by t.teamId
into grp
let maxcomp = grp.Max(g => g.compId)
from g in grp
where g.compId == maxcomp
select g).Distinct();
var filteredteams = homemax.Union(awaymax).OrderBy(t => t.teamName).AsQueryable();
As you can see we want to return the following format which is passed across to a WebAPI so we cast the results to types we can relate to in the UI.
Essentially what we are trying to do is get the home and away teams from a fixture, these fixtures have a contest which relates to a competition. We then get the highest competition id from the grouping and then this is returned with that team. The country is related to the team based on the venue id, when I was originally doing this i had problems figuring out how to do OR joins in linq which is why i split it down to getting home teams and away team and then grouping them based on competition then unioning them together.
An idea of current table size is fixtures has 7840 rows, teams has 8581 rows, contests has 337 rows and competitions has 96 rows. The table that is likely to increase rapidly is the fixture table as this is related to football.
The output we want to end up with is
Team Id, Team Name, Country Id, Country Name, Competition Id, Competition Name
Using no filtering this query takes on average around 5 secs, just wondering if anybody has any ideas/pointers on how to make it quicker.
thanks in advance Mark
I can't judge whether it will speed up things, but your homemax and awaymax queries could be
var homemax = from t in homecomps
group t by t.teamId into grp
select grp.OrderByDescending(x => x.compId).FirstOrDefault();
var awaymax = from t in awaycomps
group t by t.teamId into grp
select grp.OrderByDescending(x => x.compId).FirstOrDefault();
Further, as you are composing one very large query it may perform better when you cut it up in a few smaller queries that fetch intermediary results. Sometimes a few more roundtrips to the database perform better than one very large query for which the database engine can't find a good execution plan.
Another thing is all these Distinct()s. Do you always need them? I think you can do without because you are always fetching data from one table without joining a child collection. Removing them may save a bunch.
Yet another optimization could be to remove the ToUpper. The comparison is done by the database engine in SQL and chances are that the database has a case-insensitive collation. If so, the comparison is never case sensitive even if you'd want it to be! Constructs like Name.ToUpper cancel the use of any index on Name (it is not sargable).
The following code works, but it's not a nice code. (low performance)
I have a dictionary with value and key.
First i go trough every webcodes who exist. Then i load all participants in a list (where webcode equals the actual webcode in the foreach). After that i add the data (parameter of the webcode and a count of participants to the dictionary).
Guid compID = Guid.Parse(wID);
ChartModel webcodes = new ChartModel();
webcodes.Title = "Webcodes Statistics";
webcodes.Data = new Dictionary<string, int>();
var webcodesData = db.t_Webcode;
foreach (var w in webcodesData)
{
var wData = db.t_Participant.Where(t => t.FK_Competition == compID && t.Webcode == w.Webcode);
if (wData.Count() != 0)
webcodes.Data.Add(w.Parameter, wData.Count());
}
ViewBag.Webcodes = webcodes;
TIA
You need something along these lines:
webcodes.Data = (from w in db.t_Webcode
join p in db.t_Participant on w.Webcode equals p.Webcode
where p.FK_Competition == compID
group w by w.Parameter into g
select new { g.Key, Count = g.Count() }).ToDictionary();
I can't test it but that is the type of query you need.
This will assume that you have relationships defined in your database and that your LINQ to SQL datacontext are aware of them. If not, you will need to join manually on t_Participants from tWebcode.
This should execute in 1 single SQL query, instead of 1 query per row in tWebcode.
var webcodesAndNoOfParticipants =
from webcode in db.tWebcode
// Define number of participants for this webcode
let numberOfParticipants = webcode.t_Participants.Count(participant => participant.FK_Competition == compID)
where numberOfParticipants > 0
select new {
WebcodeParameter = webcode.Parameter,
NoOfParticipants = numberOfParticipants
};
webcodes.Data = webcodesAndNoOfParticipants.ToDictionary(x => x.WebcodeParameter, x => x.NoOfParticipants);
I have 2 tables, and want to get records from 1 table and to "update" one of its fields from another table, and to pass final list of "Payment" objects somewhere. I cannot use anonymouse type, i need to get the list of proper typed objects.
There was a long way.
Got data:
var paymentsToShow = from p in paymentsRepository.Payments
join r in recordTypeRepository.RecordType
on p.RecordType equals r.Reference into p_r
where p.Customer == CustomerRef
from r in p_r.DefaultIfEmpty()
select new
{
Payment = p,
RecordType = r
};
var objList = paymentsToShow.ToList();
Change required field (basically, Payment.RecordTypeName is empty):
foreach (var obj in objList)
{
obj.Payment.RecordTypeName = obj.RecordType.Name;
}
Got list with correct type:
var paymentsList = from o in objList
select o.Payment;
Is there any way to get code shorter, to make required field update in the query or something else? I dont know where to look for.
I cannot change database.
You could do it like this:
var paymentsToShow = (from p in paymentsRepository.Payments
join r in recordTypeRepository.RecordType
on p.RecordType equals r.Reference into p_r
where p.Customer == CustomerRef
from r in p_r.DefaultIfEmpty()
select new
{
Payment = p,
RecordType = r
}).Select(x =>
{
x.Payment.RecordTypeName = x.RecordType.Name;
return x.Payment;
});
This will result in an IEnumerable<Payment>, so no anonymous type used.
Hello everyone,
I tried and tried to make this query in vb.net, but I can not.
I do not understand if I have to use two groups, and if so, how do I use them.
This is a query that is in the project - tutorial Tailspin SpyWorks
and should serve to show the 5 most popular products.
I do not understand really how to do.
var query = (from ProductOrders in db.OrderDetails
join SelectedProducts in db.Products on ProductOrders.ProductID
equals SelectedProducts.ProductID
group ProductOrders by new
{
ProductId = SelectedProducts.ProductID,
ModelName = SelectedProducts.ModelName
} into grp
select new
{
ModelName = grp.Key.ModelName,
ProductId = grp.Key.ProductId,
Quantity = grp.Sum(o => o.Quantity)
} into orderdgrp
where orderdgrp.Quantity > 0
orderby orderdgrp.Quantity descending
select orderdgrp).Take(5);
I tried to do the translation but I can not find documentation that helps me understand how do I manage two groups.
Dim query = (From ProductOrders in db.OrderDetails
Join SelectedProducts in db.Products On
ProductOrders.ProductID Equals SelectedProducts.ProductID
Group ProductOrders By New With
{
.ProductId = SelectedProducts.ProductID,
.ModelName = SelectedProducts.ModelName
} into grp
In fact from now on I can not go on
If someone can please help me out
Thanks a lot
Fabrizio
Im not an expert of VB language, but the following code is syntactically correct:
Dim query = (From ProductOrders In Products
Join SelectedProducts In SelProducts On ProductOrders.ProductId Equals SelectedProducts.ProductId
Group ProductOrders By Key = New With {
.ProductId = SelectedProducts.ProductId,
.ModelName = SelectedProducts.ModelName
} Into grp = Group
Select orderdgrp = New With
{
.ModelName = Key.ModelName,
.ProductId = Key.ProductId,
.Quantity = grp.Sum(Function(o) o.Quantity)
}
Where orderdgrp.Quantity > 0
Order By orderdgrp.Quantity Descending
Select orderdgrp).Take(5)
Verify that the query is also semantically correct.