I am currently working with this schema
This is how my LINQ currently looks
var regionResults = (
from p in _context.Projects
from pr in p.Regions
where (data.RegionId == null || pr.RegionId == data.RegionId)
group p by pr.RegionId into g
join q in _context.Regions on g.Key equals _context.Regions.First().Id
select new Models.ViewModels.ProjectBreakdownViewModel.Regions
{
RegionName = q.Name,
TotalCount = g.Count(),
RejectedCount = g.Count(e => e.SubmissionStatusId == 2),
DeniedCount = g.Count(e => e.SubmissionStatusId == 3)
});
this is what it is currently producing, albeit incorrect
This is what I need it to be...
I know the problem is with this line, essentially
join q in _context.Regions on g.Key equals _context.Regions.First().Id
I don't know how to do this without the use of .First(), there doesn't seem to be a way to do it. I'm close I just don't know how to finish this.
If you have an collection of ProjectRegions in you Region entity, you can do this:
var result= context.Regions
.Where(r=> data.RegionId == null || r.Id == data.RegionId)
.Select(r=> new
{
RegionName = r.Name,
TotalCount = r.ProjectRegions.Count(),
RejectedCount = r.ProjectRegions.Count(e => e.Project.SubmissionStatusId == 2),
DeniedCount = r.ProjectRegions.Count(e => e.Project.SubmissionStatusId == 3)
});
ProjectRegion entity should have two nav properties, Project and Region, use them to navigate and create the corresponding conditions
Related
I am using .NET core and trying to write a Linq query to list Cases. I have 3 tables that I am trying to join together:
Cases - Includes CaseID and CaseStatusID
CaseStatuses - Includes CaseStatusID (a Case has one of these)
CaseStatusHistory - Includes CaseStatusHistoryID, CaseID, CaseStatusID (a Case has many of these).
I can join Cases and CaseStatuses easily on CaseStatusID but am not sure how to join CaseStatusHistory on CaseStatusHistoryID = a subquery selecting the MAX(CaseStatusHistoryID) WHERE CaseID and CaseStatusID matches. I could even select the CaseStatusHitory later in my results but am not sure how.
This is what I need to convert
SELECT
c.CaseID,
csh.DateTimeAdded
FROM dbo.Cases c
JOIN dbo.CaseStatuses cs
ON c.CaseStatusID = cs.CaseStatusID
LEFT JOIN dbo.CaseStatusHistory csh
ON csh.CaseStatusHistoryID =
(
SELECT MAX(CaseStatusHistoryID)
FROM dbo.CaseStatusHistory
WHERE CaseID = c.CaseID
AND cs.CaseStatusID = c.CaseStatusID
)
This is what I have so far in Linq
IQueryable<CasesViewModel> objs =
from c in _db.Cases
from cs in _db.CaseStatuses.Where(cs => cs.CaseStatusId == c.CaseStatusId.Value).DefaultIfEmpty()
select new CasesViewModel
{
CaseID = c.CaseId,
CaseStatus = cs.CaseStatus
//StatusChangeDate = csh.DateTimeAdded
};
I need to add something like this
From csh In CaseStatusHistories
Where
(
From _csh In CaseStatusHistories
Where _csh.CaseID = c.CaseID AndAlso _csh.CaseStatusID = c.CaseStatusID
Select _csh.CaseStatusHistoryID
).Max = csh.CaseStatusHistoryID
Here is what I have so far but it does not return any result - just seems to time out.
IQueryable<CasesViewModel> objs =
from c in _db.Cases
from cs in _db.CaseStatuses.Where(cs => cs.CaseStatusId == c.CaseStatusId.Value).DefaultIfEmpty()
from rg in _db.RepairingGarages.Where(rg => rg.RepairingGarageId == c.RepairingGarageId.Value).DefaultIfEmpty()
from rgb in _db.Businesses.Where(rgb => rgb.BusinessId == rg.BusinessId.Value).DefaultIfEmpty()
from ec in _db.EngineeringCompanies.Where(ec => ec.EngineeringCompanyId == c.EngineeringCompanyId.Value).DefaultIfEmpty()
from ecb in _db.Businesses.Where(ecb => ecb.BusinessId == ec.BusinessId.Value).DefaultIfEmpty()
from csh in _db.CaseStatusHistory.Where(csh => csh.CaseStatusHistoryId ==
(
from _csh in _db.CaseStatusHistory
where _csh.CaseId == c.CaseId && _csh.CaseStatusId == c.CaseStatusId.Value
select _csh.CaseStatusHistoryId
).Max()).DefaultIfEmpty()
select new CasesViewModel
{
CaseID = c.CaseId,
RepairingGarage = rgb.BusinessName,
Engineer = ecb.BusinessName,
CaseStatus = cs.CaseStatus,
StatusChangeDate = csh.DateTimeAdded
};
I just need to get the StatusChangeDate which is the DateTimeAdded in the CaseStatusHistory table. Cases can be at the same status more than once, so I just need the DateTimeAdded with the highest CaseStatusHistoryID for a particular Case. Thank you very much for any help.
This appears to answer my question
IQueryable<CasesViewModel> objs =
from c in _db.Cases
from cs in _db.CaseStatuses.Where(cs => cs.CaseStatusId == c.CaseStatusId.Value).DefaultIfEmpty()
from rg in _db.RepairingGarages.Where(rg => rg.RepairingGarageId == c.RepairingGarageId.Value).DefaultIfEmpty()
from rgb in _db.Businesses.Where(rgb => rgb.BusinessId == rg.BusinessId.Value).DefaultIfEmpty()
from ec in _db.EngineeringCompanies.Where(ec => ec.EngineeringCompanyId == c.EngineeringCompanyId.Value).DefaultIfEmpty()
from ecb in _db.Businesses.Where(ecb => ecb.BusinessId == ec.BusinessId.Value).DefaultIfEmpty()
select new CasesViewModel
{
CaseID = c.CaseId,
RepairingGarage = rgb.BusinessName,
Engineer = ecb.BusinessName,
CaseStatus = cs.CaseStatus,
StatusChangeDate =
(
from _csh in _db.CaseStatusHistory
where _csh.CaseId == c.CaseId && _csh.CaseStatusId == cs.CaseStatusId
orderby _csh.CaseStatusHistoryId descending
select _csh.DateTimeAdded
).FirstOrDefault()
};
The only trouble with not joining is that I am not sure if I can sort by this date now. Any better ideas? Thank you.
I have a LINQ statement that returns many columns. I need to find distinct of unique combination of two columns. What is the best way to do this.
var productAttributeQuery =
from pa in ctx.exch_productattributeSet
join pp in ctx.exch_parentproductSet
on pa.exch_ParentProductId.Id equals pp.Id
join ep in ctx.exch_exchangeproductSet
on pp.exch_parentproductId equals ep.exch_ParentProductId.Id
where pa.exch_EffBeginDate <= effectiveDateForBeginCompare
&& pa.exch_EffEndDate >= effectiveDateForEndCompare
&& pa.statuscode == StusCodeEnum.Active
where pp.exch_EffBeginDate <= effectiveDateForBeginCompare
&& pp.exch_EffEndDate >= effectiveDateForEndCompare
&& pp.statuscode == StatusCodeEnum.Active
where ep.statuscode == StatusCodeEnum.Active
select new ProductAttributeDto
{
ParentProductId = pa.exch_ParentProductId.Id,
AttributeId = pa.exch_AttributeId.Id,
AttributeValue = pa.exch_Value,
AttributeRawValue = pa.exch_RawValue
};
return productAttributeQuery.ToList();
I want to get Distinct combination of ParentProductId and AttributeId from this list
You can group by anonymous type and select keys (they will be distinct)
var query = from p in productAttributeQuery
group p by new {
p.ParentProductId,
p.AttributeId
} into g
select g.Key;
You can use same approach with you original query if you want to get distinct pairs on server side.
Another approach - project results into pairs and get distinct from them:
var query = productAttributeQuery
.Select(p => new { p.ParentProductId, p.AttributeId })
.Distinct();
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'm a LINQ Newb and I've got this query, which returns the pages in a survey. (These values are not materialized into a table, for whatever reason.)
//Group all of this data by page
var pages = from fq in db.FormQuestions
where (fq.FormId == id) && fq.Disabled == false
group fq by fq.PageNumber into p
select new DTOs.PageDTO { PageNumber = p.Key.Value };
And then I have this query, which projects all of the leaf-data into DTOs.
var questions = from fq in db.FormQuestions
join q in db.Questions on fq.QuestionId equals q.QuestionId
where (fq.FormId == id) && fq.Disabled == false
//where (fq.FormId == id) && fq.Disabled == false && fq.PageNumber == page
orderby fq.DisplayOrder
select new DTOs.FormQuestionDTO()
{
DisplayOrder = (fq.DisplayOrder.HasValue ? fq.DisplayOrder.Value : 0),
PageNumber = (fq.PageNumber.HasValue ? fq.PageNumber.Value : 0),
QuestionId = q.QuestionId,
QuestionSelectionMode = q.vts_tbQuestionSelectionMode.Description,
QuestionText = q.QuestionText,
Answers =
from answer in q.Answers
join at in db.AnswerTypes on answer.AnswerTypeId equals at.AnswerTypeID
where answer.Disabled == false
orderby answer.DisplayOrder
select new DTOs.AnswerDTO()
{
AnswerId = answer.AnswerId,
AnswerText = answer.AnswerText,
DisplayOrder = answer.DisplayOrder,
AnswerType = at.Description
}
};
Is there a way to join these two neatly? I.e., under each page DTO I want to see the QUestion DTOs, then inside of that Answer DTOs, and onward...
Also, even if I could do this all in one LINQ statement, is it preferable to build the LINQ statements separately and then merge them? This feels a bit like building temp variables in SQL in that it may be possible to build one giant query but it's a pain to maintain.
So why wouldn't something like this work?
//Group all of this data by page
var pages = from fq in db.FormQuestions
where (fq.FormId == id) && fq.Disabled == false
group fq by fq.PageNumber into p
select new DTOs.PageDTO {
PageNumber = p.Key.Value
questions = from fq in db.FormQuestions
join q in db.Questions on fq.QuestionId equals q.QuestionId
where (fq.FormId == id) && fq.Disabled == false
orderby fq.DisplayOrder
select new DTOs.FormQuestionDTO()
{
DisplayOrder = (fq.DisplayOrder.HasValue ? fq.DisplayOrder.Value : 0),
// etc as you 2nd code sample
Summary
I have a list of Transactions. Using Linq, I want to get a sum of the Cost and sum of the Quantity from this list in one query.
Grouping
My first thought is to use grouping - but I don't really have a key that I want to group on, I want just one group with the results from the whole list. So, I happen to have a property called "Parent" that will be the same for all of the transactions, so I'm using that to group on:
var totalCostQuery =
(from t in Transactions
where t.Status != GeneralStoreTransactionStatus.Inactive &&
(t.Type == GeneralStoreTransactionType.Purchase ||
t.Type == GeneralStoreTransactionType.Adjustment)
group t by t.Parent into g
select new
{
TotalCost = g.Sum(t => t.Cost.GetValueOrDefault()),
TotalQuantity = g.Sum(t => t.Quantity.GetValueOrDefault())
});
Grouping by t.Parent seems like it could be wrong. I really don't want to group at all, I just want the sum of t.Quantity and sum of t.Cost.
Is that the correct way to get a sum of two different properties or can it be done in a different way.
Assuming this is Linq to SQL or Entity Framework, you can do that:
var totalCostQuery =
(from t in Transactions
where t.Status != GeneralStoreTransactionStatus.Inactive &&
(t.Type == GeneralStoreTransactionType.Purchase ||
t.Type == GeneralStoreTransactionType.Adjustment)
group t by 1 into g
select new
{
TotalCost = g.Sum(t => t.Cost),
TotalQuantity = g.Sum(t => t.Quantity)
});
Note that you don't need to use GetValueOrDefault, null values will be ignored in the sum.
EDIT: not sure this works with Linq to NHibernate though...
Note that if you're using Linq to objects, the solution above won't be efficient, because it will enumerate each group twice (once for each sum). In that case you can use Aggregate instead:
var transactions =
from t in Transactions
where t.Status != GeneralStoreTransactionStatus.Inactive &&
(t.Type == GeneralStoreTransactionType.Purchase ||
t.Type == GeneralStoreTransactionType.Adjustment)
select t;
var total =
transactions.Aggregate(
new { TotalCost = 0.0, TotalQuantity = 0 },
(acc, t) =>
{
TotalCost = acc.TotalCost + t.Cost.GetValueOrDefault(),
TotalQuantity = acc.TotalQuantity + t.Quantity.GetValueOrDefault(),
});