I'm trying to execute a LINQ to Entity query which involves nested members. Below is the Entity schema. I'm keeping the code to a minimum for brevity.
public class NAVSummary
{
public virtual IList<NAVStatus> Statuses { get; set; }
}
public class NAVStatus
{
[Key]
[Column(Order = 0), ForeignKey("NAVSummary")]
public string Portfolio { get; set; }
[Key]
[Column(Order = 1), ForeignKey("NAVSummary")]
public DateTime ValueDate { get; set; }
[Key, Column(Order = 3)]
public int StatusId { get; set; }
[JsonIgnore]
public virtual NAVSummary NAVSummary { get; set; }
[ForeignKey("StatusId")]
public NAVStatusMaster StatusMaster { get; set; }
}
[Table("NAVRec_StatusMaster")]
public class NAVStatusMaster
{
[Key]
public int Id { get; set; }
public string Description { get; set; }
}
The DbContext has DbSet's for all the above Entity's.
I have the following LINQ query:
var navSummariesTemp = dbContext.NAVSummaries
.Include(n => n.Statuses)
.Include(n => n.Comments)
.Include(n => n.Statuses.Select(s => s.StatusMaster))
.Include(n => n.Extracts)
.Join(dbContext.NAVSummaries,
current => new
{
current.Portfolio,
PD = SqlFunctions.DatePart("dw", current.ValueDate) == 2 ? DbFunctions.AddDays(current.ValueDate, -3).Value :
SqlFunctions.DatePart("dw", current.ValueDate) == 1 ? DbFunctions.AddDays(current.ValueDate, -2).Value :
DbFunctions.AddDays(current.ValueDate, -1).Value
},
previous => new { previous.Portfolio, PD = previous.ValueDate },
(outer, inner) => new { outer, inner })
.Where(w => w.outer.Statuses.Count > 0)
.Select(s => new
{
DayOverDayChange = s.outer.DifferencePercent - s.inner.DifferencePercent,
IsChange = s.inner.DifferencePercent == s.outer.DifferencePercent ? false : true,
Statuses = s.outer.Statuses
}).Take(10).ToList();
The above query yields everything except the NAVStatus.StatusMaster property. Although I have included the property at the start of the query using the Include() extension, the public NAVStatusMaster StatusMaster { get; set; } is still null.
However, when I execute the below query, the StatusMaster field does get set from the database record.
var statusResult = dbContext.NAVSummaries
.Include(n => n.Statuses)
.Include(n => n.Comments)
.Include(n => n.Statuses.Select(s => s.StatusMaster))
.Include(n => n.Extracts)
.Where(n => n.Statuses.Count > 0).First();
Really appreciate if someone could help me resolve this issue.
Eager loading only works on the last part of the query. If you use projection after the includes, everything is silently lost. The only solution to your problem is to specifically put the StatusMaster inside your projection:
.Select(s => new
{
DayOverDayChange = s.outer.DifferencePercent - s.inner.DifferencePercent,
IsChange = s.inner.DifferencePercent == s.outer.DifferencePercent ? false : true,
Statuses = s.outer.Statuses,
Statusmaster = s.outer.Statuses.SelectMany(s => s.StatusMaster)
}).Take(10).ToList();
However I don't think you really want the StatusMaster to be a separate list. Perhaps it would work to do your include at the end inside the select:
.Select(s => new
{
DayOverDayChange = s.outer.DifferencePercent - s.inner.DifferencePercent,
IsChange = s.inner.DifferencePercent == s.outer.DifferencePercent ? false : true,
Statuses = s.outer.Statuses.Include(s => s.StatusMaster),
}).Take(10).ToList();
I'm not sure this will work though and can't test it as I have to go be somewhere :) The best option would be in my opinion to just make the StatusMaster virtual to enable lazy loading.
(See this link)
Related
I have the following query:
var catInclude = _db.Cat
.Where(x => x.ProvId == request.ProvId)
.Include(x => x.CatItems)
.SingleOrDefault(p => p.Id == request.ProvId
cancellationToken: cancellationToken);
As I don't want to get all properties from CatItems with Include(), I have created the following query:
var catSelect = _db.Cat
.Where(x => x.ProvId == request.ProvId)
.Select(p ==> new
{ Provider = p,
Items = p.CatItems.Select(x => new List<CatItems> { new CatItems
{ Id = x.Id, Name = x.Name, Price = x.Price } }
})})
SingleOrDefault(cancellationToken: cancellationToken);
But something is wrong in the 2nd query because here return _mapper.ProjectTo<CatDto>(cat) I get the following error:
Argument 1: cannot convert from '<anonymous type: Db.Entities.Cat Prov, System.Colletions.Generic.IEnumerable<System.Colletions.Generic.List<Models.CatItems> > Items>' to 'System.Linq.IQueryable'
Here is my CatDto:
public class CatDto
{
public int ProvId { get; set; }
public List<CatItems> CatItems { get; set; }
}
Here are my entities:
public class Prov
{
public int Id { get; set; }
public Cat Cat { get; set; }
}
public class Cat
{
public int Id { get; set; }
public int ProvId { get; set; }
public List<CatItems> CatItems { get; set; }
}
public class CatItems
{
public int Id { get; set; }
public int CatId { get; set; }
public DateTime CreatedOn { get; set; }
}
Is there a way to recreate the 2nd query and use it?
Main difference that instead of returning List of CatItems, your code returns IEnumerable<List<CatItems>> for property Items.
So, just correct your query to project to List:
var catSelect = await _db.Cat
.Where(x => x.ProvId == request.ProvId)
.Select(p => new CatDto
{
ProvId = p.ProvId,
Items = p.CatItems.Select(x => new CatItems
{
Id = x.Id,
Name = x.Name,
Price = x.Price
})
.ToList()
})
.SingleOrDefaultAsync(cancellationToken: cancellationToken);
I mean, even the exception is pretty self-explanatory. Nevertheless:
You are performing a .Select(...). It returns an Anonymous type. So, your catSelect is an anonymous type, thus the AutoMapper fails.
The quickest fix is to just cast (Cat)catSelect before mapping.
Or, you can dig deeper into how does AutoMapper play with anonymous types.
I feel like you can make most of the classes inherent Id and why is public cat CAT {get; set;} i thought you were supposed to initialize some kind of value
I have SQL query like this
SELECT T.*
FROM
(
SELECT ServiceRecords.DistrictId, Districts.Name as DistrictName, COUNT(Distinct(NsepServiceRecords.ClientRegNo)) AS ClientsServedCount
FROM ServiceRecords
INNER JOIN Districts ON ServiceRecords.DistrictId = Districts.ID
INNER JOIN NsepServiceRecords ON NsepServiceRecords.ServiceRecordId = ServiceRecords.Id
WHERE ServiceRecords.CreatedAtUtc >= #StartDate
AND ServiceRecords.CreatedAtUtc <= #EndDate
AND ServiceRecords.DistrictId = #DistrictId
GROUP BY ServiceRecords.DistrictId, Districts.Name
) AS T
ORDER BY T.DistrictName ASC, T.DistrictId
Query results:
DistrictId DistrictName ClientsServedCount
8d059005-1e6b-44ad-bc2c-0b3264fb4567 Bahawalpur 117
27ab6e24-50a6-4722-8115-dc31cd3127fa Gujrat 492
14b648f3-4912-450e-81f9-bf630a3dfc72 Jhelum 214
8c602b99-3308-45b5-808b-3375d61fdca0 Lodhran 23
059ffbea-7787-43e8-bd97-cab7cb77f6f6 Muzafarghar 22
580ee42b-3516-4546-841c-0bd8cef04df9 Peshawar 211
I'm struggling converting this to LINQ to entities query. I want to get same results (except District Id column) using LINQ.
I have tried like this, but not working as expected. Can somebody tell me what I'm doing wrong?
_dbContext.ServiceRecords
.Include(x => x.District)
.Include(x=>x.NsepServiceRecords)
.GroupBy(x => x.DistrictId)
.Select(x => new DistrictClientsLookUpModel
{
DistrictName = x.Select(record => record.District.Name).FirstOrDefault(),
ClientsServedCount = x.Sum(t=> t.NsepServiceRecords.Count)
});
Model classes are like this
public class BaseEntity
{
public Guid Id { get; set; }
}
public class NsepServiceRecord : BaseEntity
{
public DateTime CreatedAtUtc { get; set; }
public Guid ServiceRecordId { get; set; }
public string ClientRegNo { get; set; }
// other prop .......
public virtual ServiceRecord ServiceRecord { get; set; }
}
public class ServiceRecord : BaseEntity
{
public DateTime CreatedAtUtc { get; set; }
public string DistrictId { get; set; }
public virtual District District { get; set; }
public virtual ICollection<NsepServiceRecord> NsepServiceRecords { get; set; }
}
public class DistrictClientsLookUpModel
{
public string DistrictName { get; set; }
public int ClientsServedCount { get; set; }
}
I'm using Microsoft.EntityFrameworkCore, Version 2.2.4
EDIT
I have also tried like this
var startUniversalTime = DateTime.SpecifyKind(request.StartDate, DateTimeKind.Utc);
var endUniversalTime = DateTime.SpecifyKind(request.EndDate, DateTimeKind.Utc);
return _dbContext.NsepServiceRecords
.Join(_dbContext.ServiceRecords, s => s.ServiceRecordId,
r => r.Id, (s, r) => r)
.Include(i => i.District)
.Where(x => x.DistrictId == request.DistrictId
&& x.CreatedAtUtc.Date >= startUniversalTime
&& x.CreatedAtUtc.Date <= endUniversalTime)
.OrderBy(x => x.DistrictId)
.GroupBy(result => result.DistrictId)
.Select(r => new DistrictClientsLookUpModel
{
DistrictName = r.Select(x=>x.District.Name).FirstOrDefault(),
ClientsServedCount = r.Sum(x=>x.NsepServiceRecords.Count())
});
Another try,
from s in _dbContext.ServiceRecords
join record in _dbContext.NsepServiceRecords on s.Id equals record.ServiceRecordId
join district in _dbContext.Districts on s.DistrictId equals district.Id
group s by new
{
s.DistrictId,
s.District.Name
}
into grp
select new DistrictClientsLookUpModel
{
DistrictName = grp.Key.Name,
ClientsServedCount = grp.Sum(x => x.NsepServiceRecords.Count)
};
It takes too long, I waited for two minutes before I killed the request.
UPDATE
EF core have issues translating GroupBy queries to server side
Assuming the District has a collection navigation property to ServiceRecord as it should, e.g. something like
public virtual ICollection<ServiceRecord> ServiceRecords { get; set; }
you can avoid the GroupBy by simply starting the query from District and use simple projection Select following the navigations:
var query = _dbContext.Districts
.Select(d => new DistrictClientsLookUpModel
{
DistrictName = d.Name,
ClientsServedCount = d.ServiceRecords
.Where(s => s.CreatedAtUtc >= startUniversalTime && s.CreatedAtUtc <= endUniversalTime)
.SelectMany(s => s.NsepServiceRecords)
.Select(r => r.ClientRegNo).Distinct().Count()
});
You don't appear to be doing a join properly.
Have a look at this:
Join/Where with LINQ and Lambda
Here is a start on the linq query, I'm not sure if this will give you quite what you want, but its a good start.
Basically within the .Join method you need to first supply the entity that will be joined. Then you need to decide on what they will be joined on, in this case district=> district.Id, serviceRecord=> serviceRecord.Id.
_dbContext.ServiceRecords
.Join( _dbContext.District,district=> district.Id, serviceRecord=> serviceRecord.Id)
.Join(_dbContext.NsepServiceRecords, Nsep=> Nsep.ServiceRecord.Id,district=>district.Id)
.GroupBy(x => x.DistrictId)
.Select(x => new DistrictClientsLookUpModel
{
DistrictName = x.Select(record => record.District.Name).FirstOrDefault(),
ClientsServedCount = x.Sum(t=> t.NsepServiceRecords.Count)
});
I have the following models
public class Person
{
public int PersonId { get; set; }
public string Name { get; set; }
public List<PersonRole> PersonRoles { get; set; }
}
public class RoleInDuty
{
public int roleInDutyId { get; set; }
public string Name { get; set; }
public int typeOfDutyId { get; set; }
public TypeOfDuty typeOfDuty { get; set; }
public List<PersonRole> PersonRoles { get; set; }
}
public class PersonRole
{
public int PersonId { get; set; }
public Person Person { get; set; }
public int RoleInDutyId { get; set; }
public RoleInDuty RoleInDuty { get; set; }
}
And now I can load all people with all their roles using the following code:
var people = _context.Persons
.Include(p => p.PersonRoles)
.ThenInclude(e => e.RoleInDuty).ToList();
But I wantn't load all data to List, I need load PersonRole according entered typeOfDutyId.
I am trying to solve this with the following code
people = _context.Persons
.Include(p => p.PersonRoles
.Where(t=>t.RoleInDuty.typeOfDutyId == Id)).ToList();
But VS throw error
InvalidOperationException: The Include property lambda expression 'p
=> {from PersonRole t in p.PersonRoles where ([t].RoleInDuty.typeOfDutyId == __typeOfDuty_typeOfDutyId_0) select
[t]}' is invalid. The expression should represent a property access:
't => t.MyProperty'. To target navigations declared on derived types,
specify an explicitly typed lambda parameter of the target type, E.g.
'(Derived d) => d.MyProperty'. For more information on including
related data, see http://go.microsoft.com/fwlink/?LinkID=746393.
As I understand I can't access property RoleInDuty.typeOfDutyId because i'm not include it yet.
I solved this problem with the following code
people = _context.Persons
.Include(p => p.PersonRoles)
.ThenInclude(e=>e.RoleInDuty).ToList();
foreach (Person p in people)
{
p.PersonRoles = p.PersonRoles
.Where(e => e.RoleInDuty.typeOfDutyId == Id)
.ToList();
}
Finally, filter in Include with ef core 5. Details in MSDN doc: https://learn.microsoft.com/en-us/ef/core/querying/related-data#filtered-include
Var people = _context.Persons
.Include(p => p.PersonRoles
.Where(t=>t.RoleInDuty.typeOfDutyId == Id))
.ToList();
var blogs = context.Blogs
.Include(e => e.Posts.OrderByDescending(post => post.Title).Take(5)))
.ToList();
devnull show the next How to filter "Include" entities in entity framework?, and there the same problem, I read it, and find the answer. Solve my problem can with the next:
var temp = _context.Persons.Select(s => new
{
Person = s,
PersonRoles= s.PersonRoles
.Where(p => p.RoleInDuty.typeOfDutyId == this.typeOfDuty.typeOfDutyId)
.ToList()
}).ToList();
I have a use-case with a deeply nested class hierarchy, for example like this:
public class Parent
{
public int Id { get; set; }
public List<ChildOne> Children { get; set; }
}
public class ChildOne
{
public int Id { get; set; }
public int ParentId { get; set; }
public List<ChildTwo> ChildrenTwo { get; set; }
}
public class ChildTwo
{
public int Id { get; set; }
public int Priority { get; set; }
public int ChildOneId { get; set; }
public List<ChildThree> ChildrenThree { get; set; }
}
public class ChildThree
{
public int Id { get; set; }
public int ChildTwoId { get; set; }
}
If I want to load all parent-objects and their related children levels, I'd do this:
var objects = context.Parent
.Include(parent => parent.Children)
.ThenInclude(childOne => childOne.ChildrenTwo)
.ThenInclude(childTwo => childTwo.ChildrenThree)
.ToList();
But what if I want my ChildrenTwo entities in the eager-loaded navigational property of ChildOne to be ordered by their Priority? I've done some research, and from the links below (and some others), it is apparently not directly possible in EF Core (yet):
https://github.com/aspnet/EntityFrameworkCore/issues/9445
https://github.com/aspnet/EntityFrameworkCore/issues/2919
https://github.com/aspnet/EntityFrameworkCore/issues/9067
So, how can you achieve the ordering of the ChildrenTwo above (by Priority) in a good/clean way that is fast? That probably means most of the work should happen on the DB server and not on the .NET client side. What's the best approach here?
Though it is very late to answer, but it may help the future readers:
I will explain the code:
var authorArticles = await _context.AuthorArticles
.Include(a => a.Author)
.ThenInclude(p => p.Person)
.ThenInclude(pq => pq.Qualifications)
.ThenInclude(q => q.QualificationSubject)
.Include(a => a.Author)
.ThenInclude(p => p.Person)
.ThenInclude(pp => pp.Professions)
.Include(a => a.Author)
.ThenInclude(p => p.Person)
.ThenInclude(pp => pp.Professions)
.ThenInclude(prof => prof.Profession)
.Where(aa => aa.ArticleId == articleId)
.Select(s => new AuthorArticle
{
Author = new Author
{
Affiliation = s.Author.Affiliation,
AvailableAsReviewer = s.Author.AvailableAsReviewer,
Person = new Person
{
Email = s.Author.Person.Email,
FirstName = s.Author.Person.FirstName,
LastName = s.Author.Person.LastName,
MiddleName = s.Author.Person.MiddleName,
Title = s.Author.Person.Title,
FullName = s.Author.Person.FullName,
UserId = s.Author.Person.UserId,
Professions = new Collection<PersonProfession>
{
new PersonProfession
{
// using sorting here!!
Organization = s.Author.Person.Professions
.OrderByDescending(pid => pid.ProfessionId)
.FirstOrDefault().Organization,
Profession = s.Author.Person.Professions
.OrderByDescending(pid => pid.ProfessionId)
.FirstOrDefault().Profession
}
},
Qualifications = new Collection<PersonQualification>
{
new PersonQualification
{
QualificationSubject = s.Author.Person.Qualifications
.OrderByDescending(q => q.QualificationLevelId)
.FirstOrDefault().QualificationSubject,
QualificationLevelId = s.Author.Person.Qualifications
.OrderByDescending(q => q.QualificationLevelId)
.FirstOrDefault().QualificationLevelId
}
}
}
},
IsCorresponding = s.IsCorresponding,
AuthorPosition = s.AuthorPosition
}).ToListAsync();
return authorArticles;
If you simply eager loaded the entities, then at the time of projection; which means when you are selecting the items from the query, you can recreate the object that has already been provided in slightly different way. In my case, I wanted only one profession of the person out of many and same goes for the qualification of the person.
Took help of select from Another SO great answer!
How to write 'Where Any In' in LINQ to Entity?
Here is my model :
class Chair
{
public int Id { get; set; }
public int TableId { get; set; }
public Table Table { get; set; }
}
class Table
{
public int Id { get; set; }
public ICollection<Chair> Chairs { get; set; }
public ICollection<Category> Categories { get; set; }
public Table()
{
Chairs = new List<Chair>();
Categories = new List<Category>();
}
}
class Category
{
public int Id { get; set; }
public ICollection<Table> Tables { get; set; }
}
I also got a simple list of Category :
List<Category> myCategories = new List<Category>(c,d,e);
I want to get only that Chairs that belongs to Table that got one of the Category from myCategories List. Thats what im trying to do :
var result =
ctx.Chairs.Where(x => x.Table.Categories.Any(y => myCategories.Any(z => z.Id == y.Id))).ToList();
I think its ok but what i get is error :
"Unable to create a constant value of type 'ConsoleApplication1.Category'. Only primitive types or enumeration types are supported in this context"
Try to compare with in-memory categories Ids collection, instead of categories collection.
var myCategoriesIds = myCategories.Select(c => c.Id).ToArray();
var result =
context.Chairs
.Where(
x => x.Table.Categories.Any(
y => myCategoriesIds.Contains(y.Id)))
.ToList();
this is because ctx.Chairs is a collection that is in database, you should retrieve that collection first in order to compare it with in-memory data:
var result = ctx
.Chairs
.AsEnumerable() // retrieve data
.Where(x =>
x.Table.Categories.Any(y =>
myCategories.Any(z => z.Id == y.Id)))
.ToList();
EDIT: that wouldn't be the correct thing to do if you have a lot of entities on database, what you can do is to split it into two queries:
var tables = ctx.Tables
.Where(x =>
x.Categories.Any(y =>
myCategories.Any(z => z.Id == y.Id)));
var result = ctx.Chairs
.Where(x =>
tables.Any(t=> t.Id == x.TableId))
.ToList();
You can select Ids from myCategories and use it last statement.
var CategoryIds = myCategories.Select(ct => ct.Id);
var result = ctx.Chairs.Where(x => x.Table.Categories.Any(y => CategoryIds.Any(z => z == y.Id))).ToList();