My model has Owners and Complexes. An owner can have many complexes, and a complex could theoretically have multiple owners (joint ownership). I want to be able to create new complexes and owners independently, so neither should require the other. However, when I try to add a new complex, I get this error:
Violation of PRIMARY KEY constraint 'PK_dbo.Owners'. Cannot insert duplicate key in object 'dbo.Owners'. The duplicate key value is (fcd72b09-b1ef-4894-83de-cb4897c0c401).
The statement has been terminated.
For the record, there is currently one existing owner (with the ID mentioned in the error). The owner is already associated with another complex. I should be able to add a new complex with this owner, but obviously it's not allowing me to.
What do I need to change with my model to accomodate this? Relevant code follows:
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
//modelBuilder.Entity<Complex>().ToTable("Complex");
//modelBuilder.Entity<Unit>().ToTable("Unit");
//modelBuilder.Entity<Address>().ToTable("Addresses");
//modelBuilder.Entity<Tenant>().ToTable("Tenant");
modelBuilder.Entity<ContactInfo>().ToTable("Contacts");
modelBuilder.Conventions.Remove<ManyToManyCascadeDeleteConvention>();
modelBuilder.Entity<Complex>()
.HasOptional(x => x.Owner)
.WithMany(x => x.Complexes);
modelBuilder.Entity<Unit>()
.HasOptional(x => x.Complex)
.WithMany(x => x.Units);
modelBuilder.Entity<Owner>()
.HasMany(x => x.Complexes);
base.OnModelCreating(modelBuilder);
}
}
Owner and Complex models:
public class Owner
{
[Key]
public Guid Id { get; set; }
public string Name { get; set; }
public Guid? ContactInfoId { get; set; }
[ForeignKey("ContactInfoId")]
public ContactInfo ContactInfo { get; set; }
public ICollection<StaffMember> Employees { get; set; }
public ICollection<Complex> Complexes { get; set; }
public Owner()
{
this.Id = System.Guid.NewGuid();
this.Employees = new HashSet<StaffMember>();
this.Complexes = new HashSet<Complex>();
}
public void AddEmployee(StaffMember employee)
{
Employees.Add(employee);
}
public void AddComplex(Complex complex)
{
Complexes.Add(complex);
}
}
public class Complex
{
[Key]
public Guid Id { get; set; }
public string Name { get; set; }
public Guid? OwnerId { get; set; }
[ForeignKey("OwnerId")]
public Owner Owner { get; set; }
public Guid? AddressId { get; set; }
[ForeignKey("AddressId")]
public virtual Address Address { get; set; }
public virtual ICollection<Unit> Units { get; set; }
public virtual ICollection<StaffMember> StaffMembers { get; set; }
public Complex()
{
this.Id = System.Guid.NewGuid();
this.Units = new HashSet<Unit>();
this.StaffMembers = new HashSet<StaffMember>();
}
public void AddUnit(Unit unit)
{
Units.Add(unit);
}
public void AddStaff(StaffMember staffMember)
{
StaffMembers.Add(staffMember);
}
}
Your entities aren't setup correctly. In your Complex object, you are stating that it has only 1 owner so you're setting it up as a one to many instead of a many to many. If you set it as a collection instead of an object, EF will handle the many to many table for you
Related
I have a POCO Entity named Employee.
And then I have a second POCO Entity named Case.
I want a navigation property that looks like instead this:
public class Case : BaseEntity
{
public long EmployeeId { get; set; }
public virtual Employee Employee{ get; set; }
like this:
public class Case : BaseEntity
{
public long InitialContactId { get; set; }
public virtual Employee InitialContact { get; set; }
I want to name my property InitialContact. Not Employee.
But I get this error when EF tries to create the Database:
Unable to determine the relationship represented by navigation property 'Case.InitialContact' of type 'Employee'. Either manually configure the relationship, or ignore this property from the model.
Update 1:
I got it to work like this:
public class Case : BaseEntity
{
public long InitialContactId { get; set; }
[ForeignKey("Id")]
public virtual Employee InitialContact { get; set; }
public DateTime InitalConsultDate { get; set; }
public Guid AppUserId { get; set; }
public virtual AppUser LerSpecialist { get; set; }
}
The primary key is ID in my BaseEntity. Not EmployeeId.
But I have second part to my question.
Here is my Complete Employee POCO:
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations.Schema;
using Hrsa.Core.Generic.Model.Framework.Concrete;
using Microsoft.AspNetCore.Mvc.ModelBinding;
namespace Hrsa.Core.Generic.Model.Lerd
{
public class Employee : BaseEntity
{
[BindNever]
public string Email { get; set; }
[BindNever]
public long OrganizationId { get; set; }
[BindNever]
public string Supervisor { get; set; }
[BindNever]
public string SupervisorEmail { get; set; }
[BindNever]
public string FirstName { get; set; }
[BindNever]
public string LastName { get; set; }
public string Notes { get; set; }
[BindNever]
public long BargainingUnitId { get; set; }
[BindNever]
public long PayPlanId { get; set; }
[BindNever]
public long GradeRankId { get; set; }
[BindNever]
public long PositionTitleId { get; set; }
[BindNever]
public long SeriesId { get; set; }
public bool IsUnionEmployee { get; set; }
public virtual Organization Organization { get; set; }
public virtual BargainingUnit BargainingUnit { get; set; }
public virtual PayPlan PayPlan { get; set; }
public virtual GradeRank GradeRank { get; set; }
public virtual PositionTitle PositionTitle { get; set; }
public virtual Series Series { get; set; }
public virtual ICollection<UnionHours> UnionHours { get; set; }
public virtual ICollection<Case> Cases { get; set; }
[NotMapped]
public string UnionEmployeeYesNo => (IsUnionEmployee) ? "Yes" : "No";
}
}
I want my Employee to have many Cases:
public virtual ICollection<Case> Cases { get; set; }
Here is my complete Cases POCO:
public class Case : BaseEntity
{
public long InitialContactId { get; set; }
[ForeignKey("Id")]
public virtual Employee InitialContact { get; set; }
public DateTime InitalConsultDate { get; set; }
public Guid AppUserId { get; set; }
public virtual AppUser LerSpecialist { get; set; }
}
So now my DB looks like this:
So I have my InitialContactId in Cases ok.
But now I need my Case to have many Employees.
So I add this in to my Case POCO:
public virtual ICollection<Employee> Employees { get; set; }
Now it looks like this:
public class Case : BaseEntity
{
public long InitialContactId { get; set; }
[ForeignKey("Id")]
public virtual Employee InitialContact { get; set; }
public DateTime InitalConsultDate { get; set; }
public Guid AppUserId { get; set; }
public virtual AppUser LerSpecialist { get; set; }
public virtual ICollection<Employee> Employees { get; set; }
}
Now when I run it, I get this error again:
Unable to determine the relationship represented by navigation property 'Case.InitialContact' of type 'Employee'. Either manually configure the relationship, or ignore this property from the model.
Update 2:
I found this article for a Many-Many relationship in .Net Core 1:
http://www.learnentityframeworkcore.com/configuration/many-to-many-relationship-configuration
So now I have a bridge lookup entity:
public class EmployeeCase
{
[ForeignKey("Id")]
public long EmployeeId { get; set; }
public Employee Employee { get; set; }
[ForeignKey("Id")]
public long CaseId { get; set; }
public Case Case { get; set; }
}
Employee POCO:
Changed:
public virtual ICollection<Case> Cases { get; set; }
to:
// Mapping - Collection of Cases
public virtual ICollection<EmployeeCase> EmployeeCases { get; set; }
Case POCO:
Changed:
public virtual ICollection<Employee> Employees { get; set; }
to:
// Mapping - Collection of Employees
public virtual ICollection<EmployeeCase> EmployeeCases { get; set; }
In my AppDbContext
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
#region Many-to-Many Employees Cases
modelBuilder.Entity<EmployeeCase>()
.HasKey(ec => new { ec.EmployeeId, ec.CaseId });
modelBuilder.Entity<EmployeeCase>()
.HasOne(ec => ec.Employee)
.WithMany(e => e.EmployeeCases)
.HasForeignKey(ec => ec.EmployeeId);
modelBuilder.Entity<EmployeeCase>()
.HasOne(ec => ec.Case)
.WithMany(c => c.EmployeeCases)
.HasForeignKey(ec => ec.CaseId);
#endregion
}
Now when I run I get this error:
An exception of type 'System.Data.SqlClient.SqlException' occurred in Microsoft.EntityFrameworkCore.Relational.dll but was not handled in user code
Additional information: Introducing FOREIGN KEY constraint 'FK_EmployeeCase_Employees_EmployeeId' on table 'EmployeeCase' may cause cycles or multiple cascade paths. Specify ON DELETE NO ACTION or ON UPDATE NO ACTION, or modify other FOREIGN KEY constraints.
Could not create constraint or index. See previous errors.
Update 3:
Finally got my tables the way I want with this piece of code from:
Introducing FOREIGN KEY constraint may cause cycles or multiple cascade paths - why?
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
// Get rid of Cascading Circular error on ModelBuilding
foreach (var relationShip in modelBuilder.Model.GetEntityTypes().SelectMany(e => e.GetForeignKeys()))
{
relationShip.DeleteBehavior = DeleteBehavior.Restrict;
}
#region Many-to-Many Employees Cases
modelBuilder.Entity<EmployeeCase>()
.HasKey(ec => new { ec.EmployeeId, ec.CaseId });
modelBuilder.Entity<EmployeeCase>()
.HasOne(ec => ec.Employee)
.WithMany(e => e.EmployeeCases)
.HasForeignKey(ec => ec.EmployeeId);
modelBuilder.Entity<EmployeeCase>()
.HasOne(ec => ec.Case)
.WithMany(c => c.EmployeeCases)
.HasForeignKey(ec => ec.CaseId);
#endregion
base.OnModelCreating(modelBuilder);
}
Update 4:
This did not work after all.
Remvoving the delete behavior for everything messes up my other relationships and I get errors.
How can I fix this?
This is disgusting.
So wishing I did not go Core.
Entity Framework uses conventions to guess how to map your C# model to database objects.
In your case you violate convention by custom name, so you should explain Entity Framework how to map this stuff.
There are two possible ways: attributes and fluent API. I'd suggest to use the latter one.
See section "Configuring a Foreign Key Name That Does Not Follow the Code First Convention" here: Entity Framework Fluent API - Relationships
I have made it a habit of explicitly defining my relationships as EF does not always get them the way I want. I like to create a Mapping folder that contains my entity maps. The fluent api works great for this and inherits from EntityTypeConfiguration.
Try this.
public class CaseMap : EntityTypeConfiguration<Case>
{
public CaseMap()
{
HasKey(m => m.Id)
HasRequired(m => m.InitialContact)
.WithMany(e => e.Cases)
.HasForeignKey(m => m.InitialContactId);
}
}
Almost forgot. You need to tell your DbContext where to find these mappings. Add this to your DbContexts OnModelCreating method.
modelBuilder.Configurations.AddFromAssembly(typeof(MyContext).Assembly);
This is what worked finally for the Cascading Delete circular references on the many-to-many in EF Core:
// Get rid of Cascading Delete Circular references error.
var type = modelBuilder.Model.GetEntityTypes().Single(t => t.Name == "Hrsa.Core.Generic.Model.Lerd.EmployeeCase");
foreach (var relationship in type.GetForeignKeys())
{
relationship.DeleteBehavior = DeleteBehavior.Restrict;
}
You have to get the Entity representing the many to many lookup only.
And from there restrict the DeleteBehavior.
I'm working on an application related to the education industry, and I have the following set of classes.
public class Person : EntityBase<long>
{
public string Surname { get; set; }
public string First { get; set; }
public string Middle { get; set; }
public Gender Gender { get; set; }
public DateTime Dob { get; set; }
}
public class Student: Person
{
public string AdmissionId { get; set; }
public string StudentId { get; set; }
public List<GuardianLink> Guardians { get; set; }
public StudentStatus Status { get; set; }
}
public class Guardian: Person
{
public GuardianType GuardianType { get; set; }
public List<GuardianLink> Students { get; set; }
}
public class GuardianLink: EntityBase<long>
{
[Required]
public Student Student { get; set; }
[Required]
public Guardian Guardian { get; set; }
public Boolean IsEmergencyContact { get; set; }
public Boolean IsAllowedToPickup { get; set; }
}
When I tried to create the database from these classes, I received an error that this would result in circular cascading deletes. So I added the following.
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<GuardianLink>()
.HasRequired(c => c.Guardian)
.WithMany()
.WillCascadeOnDelete(false);
modelBuilder.Entity<GuardianLink>()
.HasRequired(c => c.Student)
.WithMany()
.WillCascadeOnDelete(false);
}
I expected this to resolve the issue, but I'm still getting an error.
Introducing FOREIGN KEY constraint
'FK_dbo.GuardianLinks_dbo.People_Student_Id' on table 'GuardianLinks'
may cause cycles or multiple cascade paths. Specify ON DELETE NO
ACTION or ON UPDATE NO ACTION, or modify other FOREIGN KEY
constraints.
I want to configure this so that deleting a student deletes the associated links, but not the guardian, and vice versa when deleting a guardian. Why didn't this resolve the issue? What should I be doing instead?
I'll try create one-to-one relation using EF and Fluent API.
First class:
public class Game
{
public int Id { get; set; }
public Guid Token { get; set; }
public string Player { get; set; }
public virtual Field Field { get; set; }
public virtual ICollection<Move> Moves { get; set; }
public GameStatus Status { get; set; }
public DateTime StartTime { get; set; }
public DateTime? EndTime { get; set; }
public PlayerCode Winner { get; set; }
public Game()
{
Status = GameStatus.NoteDone;
StartTime = DateTime.UtcNow;
Winner = PlayerCode.None;
Field = new Field {Game = this};
Token = Guid.NewGuid();
}
}
Secong class:
public class Field : IEntity
{
public int Id { get; set; }
public virtual Game Game { get; set; }
public string CellsString { get; set; }
}
And configure relations in context
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<Game>()
.HasRequired<Field>(g => g.Field)
.WithRequiredDependent(f => f.Game);
base.OnModelCreating(modelBuilder);
}
But after this relation in DB is not created. Tables look like this
I try many variations of Fluent configuration, but no one works for me. Where i do mistake?
You can specify a mapping for foreign key if you don't wish to add it as a property to your entity class.
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
modelBuilder.Entity<Game>()
.HasRequired(g => g.Field)
.WithRequiredPrincipal(f => f.Game)
.Map(m => m.MapKey("GameId"));
}
You probably meant WithRequiredPrincipal, not WithRequiredDependent since you probably want that foreign key to be in the Field table.
my code like below
public class User
{
public int ID { get; set; }
public int BillingAddressID { get; set; }
public Address BillingAddress { get; set; }
public IList<Shipment> Shipments { get; set; }
}
public class Address
{
public int ID { get; set; }
public string Street { get; set; }
public string City { get; set; }
public string ZipCode { get; set; }
}
public class Shipment
{
public int ID { get; set; }
public string State { get; set; }
public int DeliveryAddressID { get; set; }
public Address DeliveryAddress { get; set; }
public User ShipUser { get; set; }
//[ForeignKey("ShipUser")]
public int ShipUserID { get; set; }
//public int UserId { get; set; }
}
public class TestContext : DbContext
{
public DbSet<User> Users { get; set; }
public DbSet<Address> Addresses { get; set; }
public DbSet<Shipment> Shipments { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<Shipment>().HasRequired(u => u.ShipUser)
.WithMany(d => d.Shipments)
.HasForeignKey(c => c.ShipUserID)
.WillCascadeOnDelete(false);
}
}
if i remove the override method,i will get an error "SqlException: Introducing FOREIGN KEY constraint 'FK_Shipments_Users_ShipUserID' on table 'Shipments' may cause cycles or multiple cascade paths. Specify ON DELETE NO ACTION or ON UPDATE NO ACTION, or modify other FOREIGN KEY constraints.
Could not create constraint. See previous errors."
if i remove ShipUserID in Shipment Class,it will work ok,when i see the table that is created by ef,i found a column named Shipment_UserID in table Shipment.I don`t know why.
if rename the class indenty key to UserID,it also work ok.
I try it anyway,but I don`t know the reason, I need some books about EF associations.
If you don't have mapping specified without cascadeDelete=false for one relationship it will create multiple cascade paths if you have tow relationships to user from Shipment.
By convention you can use public
Public User ShipUser { get; set; }
public int ShipUserID { get; set; }
it will use ShipUserID as foreign key by convention.
If you remove ShipUserID Ef need to create his own foreign key to keep the relationship . that is your ' Shipment_UserID'
rename the class indenty key to UserID I don't understand what you meant.
Here is a good tutorial to start with
I have two tables (Table A, Table B) joined with a join table (TableAB) with 3 payload columns. By Payload I mean columns apart from Id, TableAId, and TableBId.
I can insert into all tables successfully, but I need to insert data into one of the payload columns on Insert. I'm using EF 4.3, Fluent API. Can anyone help? Thanks in advance.
public class Organisation : EntityBase<int>, IAggregateRoot
{
public string Name { get; set; }
public string Url { get; set; }
public int CountryId { get; set; }
public int? OwnershipTypeId { get; set; }
public int OrganisationStatusId { get; set; }
public virtual ICollection<Feature> Features { get; set; }
public virtual ICollection<OrganisationType> OrganisationTypes { get; set; }
public virtual ICollection<PricePlan> PricePlans { get; set; }
public virtual ICollection<User> Users { get; set; }
}
public class User: EntityBase<Guid>, IAggregateRoot
{
public string FirstName { get; set; }
public string LastName { get; set; }
public string JobTitle { get; set; }
public int? PhoneCallingCodeId { get; set; }
public int? PhoneAreaCode{ get; set; }
public string PhoneLocal { get; set; }
public int? MobileCallingCodeId { get; set; }
public int? MobileAreaCode { get; set; }
public string MobileLocal { get; set; }
public virtual ICollection<Organisation.Organisation> Organisations { get; set; }
}
public class OrganisationUser : EntityBase<int>, IAggregateRoot
{
public DateTime StartDate { get; set; }
public DateTime? EndDate { get; set; }
public int OrganisationRoleId {get; set;}//Foreign Key - have tried leaving it out, tried it as public virtual Organisation Organisation {get;set;
public bool IsApproved { get; set; }
}
public class SDContext : DbContext
{
public ObjectContext Core
{
get
{
return (this as IObjectContextAdapter).ObjectContext;
}
}
public IDbSet<User> User { get; set; }
public IDbSet<Organisation> Organisation { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();
modelBuilder.Entity<Organisation>().HasMany(u => u.Users).WithMany(o => o.Organisations).Map(m =>
{
m.MapLeftKey("OrganisationId");
m.MapRightKey("UserId");
m.ToTable("OrganisationUser");
});
//I have tried specifically defining the foreign key in fluent, but I really need to understand how I can add the payload properties once I access and edit them.
Your mapping is not correct for your purpose. If you want to treat OrganisationUser as an intermediate entity between Organisation and User you must create relationships between Organisation and OrganisationUser and between User and OrganisationUser, not directly between Organisation and User.
Because of the intermediate entity which contains its own scalar properties you cannot create a many-to-many mapping. EF does not support many-to-many relationships with "payload". You need two one-to-many relationships:
public class Organisation : EntityBase<int>, IAggregateRoot
{
// ...
// this replaces the Users collection
public virtual ICollection<OrganisationUser> OrganisationUsers { get; set; }
}
public class User : EntityBase<Guid>, IAggregateRoot
{
// ...
// this replaces the Organisations collection
public virtual ICollection<OrganisationUser> OrganisationUsers { get; set; }
}
public class OrganisationUser : EntityBase<int>, IAggregateRoot
{
public int OrganisationId { get; set; }
public Organisation Organisation { get; set; }
public Guid UserId { get; set; }
public User User { get; set; }
// ... "payload" properties ...
}
In Fluent API you must replace the many-to-many mapping by the following:
modelBuilder.Entity<Organisation>()
.HasMany(o => o.OrganisationUsers)
.WithRequired(ou => ou.Organisation)
.HasForeignKey(ou => ou.OrganisationId);
modelBuilder.Entity<User>()
.HasMany(u => u.OrganisationUsers)
.WithRequired(ou => ou.User)
.HasForeignKey(ou => ou.UserId);
Your derived DbContext may also contain a separate set for the OrganisationUser entity:
public IDbSet<OrganisationUser> OrganisationUsers { get; set; }
It's obvious now how you write something into the intermediate table:
var newOrganisationUser = new OrganisastionUser
{
OrganisationId = 5,
UserId = 8,
SomePayLoadProperty = someValue,
// ...
};
context.OrganisastionUsers.Add(newOrganisastionUser);
context.SaveChanges();
If you want to make sure that each pair of OrganisationId and UserId can only exist once in the link table, it would be better to make a composite primary key of those two columns to ensure uniqueness in the database instead of using a separate Id. In Fluent API it would be:
modelBuilder.Entity<OrganisationUser>()
.HasKey(ou => new { ou.OrganisationId, ou.UserId });
More details about such a type of model and how to work with it is here:
Create code first, many to many, with additional fields in association table