I will appreciate if somebody can tell me why entity framework is not creating join table for following model. It is creating table for type and feature but not the table that will join them.
public class DeviceType
{
[Display(Name = "ID")]
public int DeviceTypeID { get; set; }
public string Name { get; set; }
public string Description { get; set; }
public IEnumerable<DeviceFeature> DeviceFeatures { get; set; }
}
public class DeviceFeature
{
[Display(Name = "ID")]
public int DeviceFeatureID { get; set; }
[Required]
public string Name { get; set; }
public string Description { get; set; }
public IEnumerable<DeviceType> DeviceTypes { get; set; }
}
public class DeviceFeatureView
{
public virtual IEnumerable<DeviceType> DeviceTypes { get; set; }
public virtual IEnumerable<DeviceFeature> DeviceFeatures { get; set;
}
You do not need the bridge to create a many-to-many relationship. EF will figure it out. Change the type of the navigation properties from IEnumerable to ICollection like this:
public class DeviceType
{
public DeviceType()
{
this.DeviceFeatures = new HashSet<DeviceFeature>();
}
[Display(Name = "ID")]
public int DeviceTypeID { get; set; }
public string Name { get; set; }
public string Description { get; set; }
public ICollection<DeviceFeature> DeviceFeatures { get; set; }
}
public class DeviceFeature
{
public DeviceFeature()
{
this.DeviceTypes = new HashSet<DeviceType>();
}
[Display(Name = "ID")]
public int DeviceFeatureID { get; set; }
[Required]
public string Name { get; set; }
public string Description { get; set; }
public ICollection<DeviceType> DeviceTypes { get; set; }
}
More about it here.
Related
I have a question. I created a table with many to many relationships as below. What code should I write so that I can enter multiple categories when adding a product to the database?
I would be glad if you explain with an example.
For example, I can enter product.name information with the name information I received from the user, but I do not know how to save data in the relevant tables.
public class Category
{
public int CategoryId { get; set; }
public string Name { get; set; }
public string Url { get; set; }
public List<ProductCategory> ProductCategories { get; set; }
}
public class Product
{
public int ProductId { get; set; }
public string Name { get; set; }
public string Url { get; set; }
public double? Price { get; set; }
public string Description { get; set; }
public string ImageUrl { get; set; }
public bool IsApproved { get; set; }
public bool IsHome { get; set; }
public List<ProductCategory> ProductCategories { get; set; }
}
public class ProductCategory
{
public int CategoryId { get; set; }
public Category Category { get; set; }
public int ProductId { get; set; }
public Product Product { get; set; }
}
You can insert them by the join table like this:
var product = new Product { Name = "AA" };
var categories = new List<Category>
{
new Category{ Name = "a"},
new Category{ Name = "b"},
new Category{ Name = "c"},
};
foreach (var category in categories)
{
_context.ProductCategory.Add(
new ProductCategory
{
Product = product,
Category = category
});
}
_context.SaveChanges();
I am not sure which version you are using. with EF Core 5.o find an example at https://learn.microsoft.com/en-us/ef/core/what-is-new/ef-core-5.0/whatsnew
Models:
public class Category
{
public int CategoryId { get; set; }
public string Name { get; set; }
public string Url { get; set; }
public ICollection<Product> Products { get; set; }
}
public class Product
{
public int ProductId { get; set; }
public string Name { get; set; }
public string Url { get; set; }
public double? Price { get; set; }
public string Description { get; set; }
public string ImageUrl { get; set; }
public bool IsApproved { get; set; }
public bool IsHome { get; set; }
public ICollection<Category> Categories { get; set; }
}
Or If you are using EE 6 or EF Core 3.1 then your models should be like:
public class Category
{
public int CategoryId { get; set; }
public string Name { get; set; }
public string Url { get; set; }
public ICollection<Product> Products { get; set; }
public ProductCategory ProductCategorie { get; set; }
}
public class Product
{
public int ProductId { get; set; }
public string Name { get; set; }
public string Url { get; set; }
public double? Price { get; set; }
public string Description { get; set; }
public string ImageUrl { get; set; }
public bool IsApproved { get; set; }
public bool IsHome { get; set; }
public ICollection<Category> Categories { get; set; }
public ProductCategory ProductCategorie { get; set; }
}
public class ProductCategory
{
public int CategoryId { get; set; }
public Category Category { get; set; }
public int ProductId { get; set; }
public Product Product { get; set; }
}
For inserting data to Many-Many tables: https://learn.microsoft.com/en-us/aspnet/core/data/ef-mvc/complex-data-model?view=aspnetcore-5.0
then please look at the section:Seed database with test data
I have problem when I try to migrate my model in EF Core 2.0.
public class Profile
{
[Key]
public Guid Id { get; set; }
public Guid UserId { get; set; }
public ExternalUser User { get; set; }
}
public class OrganizationCustomerProfile : Profile
{
public string CompanyName { get; set; }
public Address LegalAddress { get; set; }
public Address ActualAddress { get; set; }
public BusinessRequisites Requisites { get; set; }
public string President { get; set; }
public IEnumerable<ContactPerson> ContactPerson { get; set; }
}
public class PersonCustomerProfile : Profile
{
public FullName Person { get; set; }
public Address Address { get; set; }
public string PhoneNumber { get; set; }
}
public class ContactPerson
{
[Key]
public Guid Id { get; set; }
public FullName Person { get; set; }
public string Rank { get; set; }
public string Email { get; set; }
public string PhoneNumber { get; set; }
public Guid ProfileId { get; set; }
public Profile Profile { get; set; }
}
Here I want to add complex datatypes Address and BusinessRequisites, which are:
public class BusinessRequisites
{
public string OGRN { get; set; }
public string INN { get; set; }
public string KPPCode { get; set; }
public string SettlementAccount { get; set; }
public string RCBIC { get; set; }
public string CorrespondentAccount { get; set; }
public string BankName { get; set; }
}
public class Address
{
public string FullAddress { get; set; }
public float Latitude { get; set; }
public float Longtitude { get; set; }
}
Code which I use for TPH binding:
public DbSet<Profile> UserProfiles { get; set; }
public DbSet<ContactPerson> ContactPerson { get; set; }
public DbSet<OrganizationCustomerProfile> OrganizationCustomerProfile { get; set; }
...
modelBuilder.Entity<Profile>().HasKey(u => u.Id);
modelBuilder.Entity<OrganizationCustomerProfile>().OwnsOne(e => e.ActualAddress);
modelBuilder.Entity<OrganizationCustomerProfile>().OwnsOne(e => e.LegalAddress);
modelBuilder.Entity<OrganizationCustomerProfile>().OwnsOne(e => e.Requisites);
But when I try to make a migration, I get an error:
"Cannot use table 'UserProfiles' for entity type
'OrganizationCustomerProfile.ActualAddress#Address' since it has a
relationship to a derived entity type 'OrganizationCustomerProfile'.
Either point the relationship to the base type 'Profile' or map
'OrganizationCustomerProfile.ActualAddress#Address' to a different
table."
So, what the reason of this error? Is it not possible to create hierarchy inheritance in EF Core 2.0?
Thank you!
It seems like this isn't supported at the moment:
https://github.com/aspnet/EntityFrameworkCore/issues/9888
For example, I have the following infrastructure class:
[Table("GeoHistory")]
public partial class GeoHistory
{
public int Id { get; set; }
public int CompanyId { get; set; }
public int DriverId { get; set; }
[StringLength(50)]
public string Name { get; set; }
public string Description { get; set; }
[StringLength(100)]
public string GeofenceLocation { get; set; }
[StringLength(100)]
public string GeofencePrevious { get; set; }
[StringLength(20)]
public string StateLocation { get; set; }
[StringLength(20)]
public string StatePrevious { get; set; }
public DateTime? DateTime { get; set; }
[StringLength(5)]
public string Heading { get; set; }
public decimal? Speed { get; set; }
[StringLength(50)]
public string Status { get; set; }
}
and the following View class (let's forget about domain layer):
public class GeoHistoryViewModel
{
public int Id { get; set; }
public int? CompanyId { get; set; }
public int? DriverId { get; set; }
[StringLength(50)]
public string Name { get; set; }
public string Description { get; set; }
}
as we can see, we edit only part of field list.
Now, we want to update data in DB. Of course, we can write like:
Infrastructure.Main.GeoHistory geoHistory = db.GeoHistories.Find(id);
geoHistory.CompanyId = model.CompanyId;
geoHistory.DriverId = model.DriverId;
geoHistory.Name = model.Name;
........
db.SaveChanges();
It works. But I want to use Automapper. And if I try to do the following:
Infrastructure.Main.GeoHistory geoHistory = mapper.Map<Infrastructure.Main.GeoHistory>(model);
db.GeoHistories.Attach(geoHistory);
db.Entry(geoHistory).State = EntityState.Modified;
db.SaveChanges();
It works, but of course remove values of fields, which are not exist in View Model, but exist in infrastructure class. How to use automapper, but don't lost these fields?
I want to map from
LDTTicketUploadDTO[] to IEnumerable<LDTTicket>
The mappings are created in this method and at the end I map the data.
public void UploadLDTTickets(LDTTicketUploadDTO[] ticketDTOs)
{
Mapper.CreateMap<LDTTicketUploadDTO, LDTTicket>();
Mapper.CreateMap<LDTTicketDTO, LDTTicket>();
Mapper.CreateMap<LDTCustomerDTO, LDTCustomer>();
Mapper.CreateMap<LDTDeviceDTO, LDTDevice>();
Mapper.CreateMap<LDTUnitDTO, LDTUnit>();
Mapper.CreateMap<LDTCommandDTO, LDTCommand>();
Mapper.CreateMap<LDTCommandParameterDTO, LDTCommandParameter>();
Mapper.CreateMap<LDTObjectDTO, LDTObject>();
Mapper.CreateMap<LDTControlFileDTO, LDTControlFile>();
Mapper.CreateMap<LDTDeviceDTO, LDTDevice>();
Mapper.CreateMap<LDTLanguageDTO, LDTLanguage>();
Mapper.CreateMap<LDTObjectBitDTO, LDTObjectBit>();
var tickets = Mapper.Map<IEnumerable<LDTTicketUploadDTO>, IEnumerable<LDTTicket>>(ticketDTOs);
// do something with tickets
}
This is how the DTO´s are structured:
public class LDTTicketUploadDTO
{
public LDTTicketDTO Ticket { get; set; }
public LDTDeviceDTO Device { get; set; }
public LDTCustomerDTO Customer { get; set; }
}
public enum TicketStatus
{
New,
InProgress,
Done
}
public class LDTTicketDTO
{
public bool UploadNeeded { get; set; }
public string TicketNumber { get; set; }
public TicketStatus Status { get; set; }
public string CreatedBy { get; set; }
public DateTime CreatedOn { get; set; }
public string AssignedTo { get; set; }
public IEnumerable<LDTUnitDTO> Units { get; set; }
}
public class LDTUnitDTO
{
public int Id { get; set; }
public string FunctionUnit { get; set; }
public int FunctionUnitAddress { get; set; }
public string Zone { get; set; }
public int ZoneUnitAddress { get; set; }
public string Object { get; set; }
public int ObjectAddress { get; set; }
public IEnumerable<LDTCommandDTO> Commands { get; set; }
}
and more...
What works is that these properties are correctly mapped to their counterpart entities:
public LDTDeviceDTO Device { get; set; }
public LDTCustomerDTO Customer { get; set; }
What works NOT is that this property is not mapped:
public LDTTicketDTO Ticket { get; set; }
This is how the Entities are structured:
public class LDTTicket
{
[Key, Column(Order = 0)]
[Required]
public string SerialNumber { get; set; }
[Key, Column(Order = 1)]
[Required]
public string TicketNumber { get; set; }
[Required]
public DateTime CreatedOn { get; set; }
[Required]
public string AssignedTo { get; set; }
public TicketStatus Status { get; set; }
public string CreatedBy { get; set; }
public bool UploadNeeded { get; set; }
public virtual LDTCustomer Customer { get; set; }
public virtual LDTDevice Device { get; set; }
public virtual ICollection<LDTUnit> Units { get; set; }
}
ONLY the Customer and Device property are mapped in the LDTTicket
What is wrong with my configuration?
It's expecting to populate a LDTTicket sub-property on the ticket, not the matching properties of the ticket itself. Create direct mappings onto the ticket from the Ticket subproperty of the source directly onto the matching properties of the destination. NOTE: You only need to define your mappings once, not per method execution. Mappings should be defined at app start up and thereafter used.
public void UploadLDTTickets(LDTTicketUploadDTO[] ticketDTOs)
{
Mapper.CreateMap<LDTTicketUploadDTO, LDTTicket>();
.ForMember(d => d.SerialNumber, m => m.MapFrom(s => s.Ticket.SerialNumber))
...
//Mapper.CreateMap<LDTTicketDTO, LDTTicket>(); You don't need this
Mapper.CreateMap<LDTCustomerDTO, LDTCustomer>();
Mapper.CreateMap<LDTDeviceDTO, LDTDevice>();
...
}
I have a database with 3 tables:
Subjects
Members
Topics
Then I added the connection string to web.config and created an EF with the following classes:
namespace MySite.Models
{
public class MySiteDBModel : DbContext
{
public DbSet<Topic> Topics { get; set; }
public DbSet<Subject> Subjects { get; set; }
public DbSet<Member> Members { get; set; }
public DbSet<TopicDataModel> TopicDataModel { get; set; }
protected override void OnModelCreating(DbModelBuilder mb)
{
mb.Conventions.Remove<PluralizingTableNameConvention>();
}
}
public class Topic
{
[Key]
public int TopicID { get; set; }
public int SubID { get; set; }
public int MemberID { get; set; }
public string TDate { get; set; }
public string Title { get; set; }
public string FileName { get; set; }
public int Displays { get; set; }
public string Description { get; set; }
public virtual Subject Subject { get; set; }
public virtual Member Member { get; set; }
public virtual ICollection<TopicView> TopicView { get; set; }
}
public class Subject
{
[Key]
public int SubID { get; set; }
public string SubName { get; set; }
public virtual ICollection<Topic> Topic { get; set; }
}
public class Member
{
[Key]
public int MemberID { get; set; }
public string FLName { get; set; }
public string Email { get; set; }
public string Pwd { get; set; }
public string About { get; set; }
public string Photo { get; set; }
public virtual ICollection<Topic> Topic { get; set; }
}
public class TopicDataModel
{
[Key]
public int TopicID { get; set; }
public string SubName { get; set; }
public string FLName { get; set; }
public string TDate { get; set; }
public string Title { get; set; }
public int Displays { get; set; }
public string Description { get; set; }
}
}
Now when I am trying to query the database with the this code:
public ActionResult Index()
{
var topics = from t in db.Topics
join s in db.Subjects on t.SubID equals s.SubID
join m in db.Members on t.MemberID equals m.MemberID
select new TopicDataModel()
{
TopicID = t.TopicID,
SubName = s.SubName,
FLName = m.FLName,
TDate = t.TDate,
Title = t.Title,
Displays = t.Displays,
Description = t.Description
};
return View(topics.ToList());
}
I got this Error:
The model backing the 'MySiteDBModel' context has changed since the
database was created. Either manually delete/update the database, or
call Database.SetInitializer with an IDatabaseInitializer instance.
For example, the DropCreateDatabaseIfModelChanges strategy will
automatically delete and recreate the database, and optionally seed it
with new data.
Please help me!!!!!!
You need to set some controls on how EF is handling changes to your data model. Julie Lerman has a good blog post on Turning Off Code First Database Initialization Completely.
Also, here is a good overview - Inside Code First Database Initialization