Develop Reference

EF Core child ID doesn't match Database results

I have the following classes:
[Table("Artikel_Meldung", Schema = "BDB")]
public class Artikel_Meldung
{
[Key]
public int Artikel_MeldungId { get; set; }
public int Meldung_Id { get; set; }
public Meldung Meldung { get; set; }
public Artikel Artikel { get; set; }
public long ArtNr { get; set; }
[Column(TypeName = "nvarchar(2)")]
public string Ausfkz { get; set; }
}
[Table("Meldung", Schema = "BDB")]
public class Meldung
{
[Key]
public int Meldung_Id { get; set; }
public string Erfasser { get; set; }
public Artikel ErsatzArtikel { get; set; }
[NotMapped]
public Artikel Parent { get; set; }
public long ErsatzArtNr { get; set; }
[Column(TypeName = "nvarchar(2)")]
public string ErsatzAusfKz { get; set; }
public virtual ICollection<Artikel_Meldung> Artikel_Meldungen { get; set; }
public string Kommentar { get; set; }
public DateTime StartZeitpunkt { get; set; }
public DateTime EndeZeitpunkt { get; set; }
}
And retrieving the results with the following command:
query = srv_apps_db.Artikel.Where(x => x.Artikelbezeichnung.Contains(search_string) || x.ModbezKd.Contains(search_string))
.Include(art => art.Supplier)
.Include(art => art.Warengruppe)
.Include(a => a.Inventory)
.Include(art => art.Specials.Where(spe => spe.GueltigAb <= DateTime.Now.Date && spe.GueltigBis >= DateTime.Now.Date && (spe.FilialNr == Filiale || spe.FilialNr == 0)))
.Include(art => art.Orders.Where(ord => ord.PosNr.Substring(0, 1) != "5"))
.Include(art => art.Artikel_Bilder).ThenInclude(img => img.Bild).ThenInclude(s => s.ImgTyp)
.Include(art => art.Artikel_Meldungen).ThenInclude(x=>x.Meldung);
artikel = await query.AsSplitQuery()
.AsNoTracking()
.ToListAsync();
Everything works so far, but as I inspected the retrievd objects I noticed that Meldung.Meldung_Id is always 1 off the actual value in the Database.
Json-Result of my API-Call:
{
"artikel_MeldungId": 608,
"meldung_Id": 609,
"meldung": {
"meldung_Id": 609,
"erfasser": "NZI",
"ersatzArtikel": {
"artNr": 10080405,
"ausfKz": "02",
....
}
}
The values are correct but the Id doesn't match is this a bug or an error in my code or expected behaviour on EF?
Thanks in advance
regards Tekkion

How to use Automapper to flatten list of entity hierarchies?

I want to use automapper to flatten a list of entity heirarchies returned back from Entity Framework Core.
Here are my entities:
public class Employee {
public int Id { get; set; }
[Required]
public string Name { get; set; }
public double? PayRateRegular { get; set; }
public double? PayRateLoadedRegular { get; set; }
public double? GMOutput { get; set; }
public string EmployeeType { get; set; }
//List of CommissionDetails where this employee is the consultant
public IEnumerable<CommissionDetail> CommissionDetailConsultants { get; set; } = new List<CommissionDetail>();
}
public class Project {
public int Id { get; set; }
public string Description { get; set; }
public double? BillRateRegular { get; set; }
public DateTime? StartDate { get; set; }
public DateTime? EndDate { get; set; }
public Customer Customer { get; set; }
public int CustomerId { get; set; }
}
public class Customer {
public int Id { get; set; }
public string Name { get; set; }
}
public class CommissionDetail {
public string SaleType { get; set; }
public double CommissionPercent { get; set; }
public bool? IsReported { get; set; }
public int? Level { get; set; }
public string BasedOn { get; set; }
public Project Project { get; set; }
public int ProjectId { get; set; }
public Employee SalesPerson { get; set; }
public int SalesPersonEmployeeId { get; set; }
public Employee Consultant { get; set; }
public int ConsultantEmployeeId { get; set; }
}
Here is my DTO:
public class ConsultantGridViewModel
{
public string ConsultantName { get; set; }
public string CustomerName { get; set; }
public string SalesPersonName { get; set; }
public string ProjectDescription { get; set; }
public double? PayRate { get; set; }
public double? LoadedRated { get; set; }
public double? BillRate { get; set; }
public double? GM { get; set; }
public DateTime? StartDate { get; set; }
public DateTime? EndDate { get; set; }
public double CommissionPercent { get; set; }
public int? CommissionLevel { get; set; }
}
Here is my call to EF:
return await _dbContext.Employee
.AsNoTracking()
.Include(e => e.CommissionDetailConsultants)
.ThenInclude(cd => cd.SalesPerson)
.Include(e => e.CommissionDetailConsultants)
.ThenInclude(cd => cd.Project)
.ThenInclude(p => p.Customer)
.Where(e => e.EmployeeType == "Contractor")
.ToListAsync();
I'm currently flattening it with SelectMany as follows:
var consultants = employees.SelectMany(e =>
e.CommissionDetailConsultants,
(emp, com) => new ConsultantGridViewModel {
ConsultantName = emp.Name,
PayRate = emp.PayRateRegular,
LoadedRated = emp.PayRateLoadedRegular,
GM = emp.GMOutput,
BillRate = com.Project.BillRateRegular,
ProjectDescription = com.Project.Description,
ProjectStartDate = com.Project.StartDate,
ProjectEndDate = com.Project.EndDate,
CustomerName = com.Project.Customer.Name,
SalesPersonName = com.SalesPerson.Name,
CommissionPercent = com.CommissionPercent,
CommissionLevel = com.Level
});
I would like to use automapper instead. I've used automapper for all my other DTO mappings but I can't figure out how to use it to flatten a nested object like this.

Let rewrite what you have currently with SelectMany + Select utilizing the Consultant navigation property:
var consultants = employees
.SelectMany(e => e.CommissionDetailConsultants)
.Select(com => new ConsultantGridViewModel
{
ConsultantName = com.Consultant.Name,
PayRate = com.Consultant.PayRateRegular,
LoadedRated = com.Consultant.PayRateLoadedRegular,
GM = com.Consultant.GMOutput,
BillRate = com.Project.BillRateRegular,
ProjectDescription = com.Project.Description,
ProjectStartDate = com.Project.StartDate,
ProjectEndDate = com.Project.EndDate,
CustomerName = com.Project.Customer.Name,
SalesPersonName = com.SalesPerson.Name,
CommissionPercent = com.CommissionPercent,
CommissionLevel = com.Level
});
Now it can be seen that the CommissionDetail contains all the necessary data, so while you can't avoid SelectMany, you can replace the Select by creating a mapping from CommissionDetail to ConsultantGridViewModel and use something like this:
var consultants = Mapper.Map<List<ConsultantGridViewModel>>(
employees.SelectMany(e => e.CommissionDetailConsultants));
or even better, project directly to the DTO:
var consultants = await _dbContext.Employee
.Where(e => e.EmployeeType == "Contractor")
.SelectMany(e => e.CommissionDetailConsultants)
.ProjectTo<ConsultantGridViewModel>()
.ToListAsync();
Now the mapping.
AutoMapper will map automatically members like CommisionPercent. Also the Flattening feature will handle automatically mappings like Project.EndDate -> ProjectEndDate, Consultant.Name -> ConsultantName etc.
So as usual with AutoMapper you should specify manually the mapping of properties which don't fall into previous categories. The minimal configuration in this case would be something like this:
Mapper.Initialize(cfg =>
{
cfg.CreateMap<CommissionDetail, ConsultantGridViewModel>()
.ForMember(dst => dst.PayRate, opt => opt.MapFrom(src => src.Consultant.PayRateRegular))
.ForMember(dst => dst.LoadedRated, opt => opt.MapFrom(src => src.Consultant.PayRateLoadedRegular))
.ForMember(dst => dst.GM, opt => opt.MapFrom(src => src.Consultant.GMOutput))
.ForMember(dst => dst.BillRate, opt => opt.MapFrom(src => src.Project.BillRateRegular))
.ForMember(dst => dst.CustomerName, opt => opt.MapFrom(src => src.Project.Customer.Name))
.ForMember(dst => dst.CommissionLevel, opt => opt.MapFrom(src => src.Level));
});
P.S. You can even avoid SelectMany by basing your queries directly on CommissionDetail entity, for instance
var consultants = await _dbContext.Set<CommissionDetail>()
.Where(c => c.Consultant.EmployeeType == "Contractor")
.ProjectTo<ConsultantGridViewModel>()
.ToListAsync();
Note that when you do direct projection, there is no need of AsNoTracking or Include / ThenInclude.

Populate multiple collections on same type

I need to populate a Product object which contains two collections.
The current code works fine and populates the Product.GraphicItems collection, but I also need to populate the Product.InfoItems collection, but I can't figure out the syntax for multiple collections.
Current select:
var result = await this.Context.ShopCategorys
.Include(cat => cat.InfoItems)
.Include(cat => cat.Products)
.ThenInclude(prd => prd.GraphicItems)
.ThenInclude(itm => itm.Graphic)
.ThenInclude(gfx => gfx.Items)
.SingleAsync(cat => cat.Id.Equals(id));
Product.cs:
[Table("ShopProduct")]
public class Product : BaseShop
{
public bool Active { get; set; } = true;
public int CategoryId { get; set; }
public int CultureId { get; set; } = -1;
public List<ProductInfo> InfoItems { get; set; } = new List<ProductInfo>();
public List<ProductGraphic> GraphicItems { get; set; } = new List<ProductGraphic>();
}
ProductInfo.cs:
[Table("ShopProductInfo")]
public class ProductInfo : BaseShop, IInfoItem
{
public int? ProductId { get; set; }
public int CultureId { get; set; }
public Culture Culture { get; set; }
public string Name { get; set; }
public string Description { get; set; }
}

Solution:
var result = await this.Context.ShopCategorys
.Include(cat => cat.InfoItems)
.Include(cat => cat.Products)
.ThenInclude(prd => prd.InfoItems)
.Include(cat => cat.Products)
.ThenInclude(prd => prd.GraphicItems)
.ThenInclude(itm => itm.Graphic)
.ThenInclude(gfx => gfx.Items)
.SingleAsync(cat => cat.Id.Equals(id));

How to write below mysql query using Entity Framework with Lambda expression?

SELECT
`Distinct1`.`UserId`,
`Distinct1`.`FirstName`,
`Distinct1`.`LastName`,
`Distinct1`.`EmailAddress`,
FROM ( SELECT DISTINCT
`Extent2`.`UserId`,
`Extent2`.`FirstName`,
`Extent2`.`LastName`,
`Extent2`.`EmailAddress`,
FROM `AssistantTo` AS `Extent1`
INNER JOIN `User` AS `Extent2` ON `Extent1`.`AssistantId` = `Extent2`.`UserId`
INNER JOIN `CustomTagUser` as `Extent3` ON `Extent3`.`UserId` = `Extent2`.`UserId`
WHERE `Extent1`.`OwnerId` = 274 AND `Extent3`.`CustomTagId` = 114
) AS `Distinct1`
This is my Table structure :
I tried using following query but it is giving me error.
var assistants =
dbContext.AssistantsTo
.Include(x => x.Assistant)
.Include(x => x.Assistant.CustomTagUser)
.Where(at =>
at.OwnerId == currentUser.UserId
&& (at.Assistant.CustomTagUser.Count(y => y.CustomTagId == filter) > 0)
)
.Select(at => at.Assistant)
.Distinct()
.ToList();
Error : {"Unknown column 'Extent1.AssistantId' in 'where clause'"}
Basically I have issue with giving filter for
`Extent3`.`CustomTagId` = 114
I think we can use any() but I have bad experience using any() with large data & mysql.
Model classes
public class AssistantTo
{
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int AssistantToId { get; set; }
public int AssistantId { get; set; }
[ForeignKey("AssistantId")]
public virtual User Assistant { get; set; }
public int OwnerId { get; set; }
[ForeignKey("OwnerId")]
public virtual User Owner { get; set; }
}
public class CustomTagUser
{
[Key]
public int CustomTagUserId { get; set; }
public int CustomTagId { get; set; }
public int UserId { get; set; }
public DateTime CreatedOn { get; set; }
[ForeignKey("CustomTagId")]
public virtual CustomTags CustomTags { get; set; }
[ForeignKey("UserId")]
public virtual User User { get; set; }
}
[Table("User")]
public class User
{
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int UserId { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public string EmailAddress { get; set; }
public string Password { get; set; }
.....
public ICollection<CustomTagUser> CustomTagUser { get; set; }
}
}
Basically I have main problem with applying this part in EF
AND Extent3.CustomTagId = 114

var assistants =
dbContext.AssistantsTo
.Include(x => x.Assistant)
.Include(x => x.Assistant.CustomTagUser)
.Where(at =>
at.OwnerId == currentUser.UserId &&
(
at.Assistant.CustomTagUser.Select(x => x.CustomTagId).Contains(filter)
)
.Select(at => at.Assistant)
.Distinct()
.ToList();
try this one...

How can I get the data from fields of an .Include in a LINQ Query?

I am using Entity Framework 5 and I have these classes. What I want to do is to be able to get the data to populate the view listed below:
public partial class Subject
{
public int SubjectId { get; set; }
public string Name { get; set; }
public virtual ICollection<Topic> Topics { get; set; }
}
public partial class Topic
{
public int TopicId { get; set; }
public string Name { get; set; }
public int SubjectId { get; set; }
public virtual Subject Subject { get; set; }
public virtual ICollection<SubTopic> SubTopics { get; set; }
}
public partial class SubTopic
{
public int SubTopicId { get; set; }
public string Name { get; set; }
public int TopicId { get; set; }
public virtual Topic Topic { get; set; }
}
Now I am trying to write a LINQ query to populate this class:
public class TopicSubTopicSelect
{
public int TopicId { get; set; }
public int SubTopicId { get; set; }
public string TopicName { get; set; }
public string SubTopicName { get; set; }
}
So far I have this:
return _subjectsRepository
.GetAll()
.Where(s => s.SubjectId == subjectId)
.Include(s => s.Topics.SelectMany(t => t.SubTopics))
.AsEnumerable()
.Select(item => new TopicSubTopicSelect(item.TopicId <<<
item.SubTopicId <<
item.Topic.Name <<
item.Name <<))
.ToList();
Can someone tell me how I can get data from the fields I marked with <<. I tried to do .item.Topic.TopicId etc but that does not seem to work.

You shouldn't start from Subject. You just start from SubTopic Repository, and you won't even need to use .Include. Do it like this:
_subTopicRepository
.GetAll()
.Where(s => s.Topic.SubjectId == subjectId)
.Select(s => new TopicSubTopicSelect()
{
TopicId = s.TopidId,
SubTopicId = s.SubTopicId,
TopicName = s.Topic.Name,
SubTopicName = s.Name
})
.ToList();

As I mentioned in my comment on ataravati's answer, you shouldn't actually have a SubTopicRepository so you are correct in starting at SubjectsRepository however you are querying by the Subject ID so you shouldn't be going via GetAll(), you should have a Get(int id) method. The include should be handled as an implementation detail inside Get as the children (SubTopics) are part of the Subject. That makes the method call look like this instead:
return _subjectsRepository
.Get(subjectId)
.SelectMany(subject => subject.SubTopics))
.Select(subTopic => new TopicSubTopicSelect
{
TopicId = subTopic.TopicId,
SubTopicId = subTopic.SubTopicId,
TopicName = subTopic.Topic.Name,
SubTopicName = subTopic.Name
}).ToList();