I have many classes representing tables, but three are giving me headaches: Person, Task, and Role, here is their code:
public class Person : BaseModel
{
public int Id { get; set; }
public string FName { get; set; }
public string LName { get; set; }
public string Title { get; set; }
public ICollection<TestEvent> TestEventsLed { get; set; }
public ICollection<TestEvent> TestEventsCreated { get; set; }
public ICollection<Program> ProgramsLed { get; set; }
public ICollection<Task> TasksCreated { get; set; }
public ICollection<PersonalEvent> PersonalEventsCreated { get; set; }
public virtual ICollection<Role> RolesHeld { get; set; }
public virtual ICollection<Task> TasksAssigned { get; set; }
}
public class Role : BaseModel
{
public int Id { get; set; }
public string Name { get; set; }
public virtual ICollection<Person> PeopleWithThisRole { get; set; }
}
public class Task : BaseModel
{
public int Id { get; set; }
public string Name { get; set; }
public DateTime SuspenseDatetime { get; set; }
public DateTime CreatedDatetime { get; set; }
public int CreatedById { get; set; }
public bool Completed { get; set; }
public bool Archived { get; set; }
public Person CreatedBy { get; set; }
public virtual ICollection<Person> PeopleAssigned { get; set; }
}
What I end up with is mostly what I wanted, except a few hiccups:
Expected: Actual:
- People should have 0 foreign keys, just - People has 1 FK and 1 extra column out of
2 many-to-manys for RolesHeld and nowhere: Task_Id and the FK is for that
TasksAssigned new column referencing Id in Tasks?
- Task should have 1 foreign key for - Task has 2 extra columns out of nowhere
CreatedById linked to a Person called Person_Id and Person_Id1 and then
identical foreign keys attached to them
(and it has the expected CreatedById FK)
- There should be a RolePersons table - This part happened correctly and with the
with 2 FKs to represent the many-to-many correct FKs to represent the many-to-many
- There should be a TaskPersons table - There is no new table at all for this
with 2 FKs to represent the many-to-many
The weird thing is, I did some of these the same way (like the two many-to-many relationships) but then only 1 turned out correctly? Can you see what I did incorrectly?
Sometime default mapping is not what we want, so we have to explicitly say to EF what we need. Just add this method to your DbContext and it works as required:
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<Person>().HasMany(p => p.TasksAssigned).WithMany(t => t.PeopleAssigned);
modelBuilder.Entity<Person>().HasMany(p => p.TasksCreated).WithRequired(t => t.CreatedBy).WillCascadeOnDelete(false);
}
Entity Framework do something by convention.
Look your Task class and Person class
public class Task : BaseModel
{
public int Id { get; set; }
public string Name { get; set; }
public DateTime SuspenseDatetime { get; set; }
public DateTime CreatedDatetime { get; set; }
public int CreatedById { get; set; }
public bool Completed { get; set; }
public bool Archived { get; set; }
public Person CreatedBy { get; set; }
public virtual ICollection<Person> PeopleAssigned { get; set; }
}
public class Person : BaseModel
{
public int Id { get; set; }
public string FName { get; set; }
public string LName { get; set; }
public string Title { get; set; }
public ICollection<TestEvent> TestEventsLed { get; set; }
public ICollection<TestEvent> TestEventsCreated { get; set; }
public ICollection<Program> ProgramsLed { get; set; }
public ICollection<Task> TasksCreated { get; set; }
public ICollection<PersonalEvent> PersonalEventsCreated { get; set; }
public virtual ICollection<Role> RolesHeld { get; set; }
public virtual ICollection<Task> TasksAssigned { get; set; }
}
In your Task Class you are putting Person object and as well as a collection of Person.That's the thing is the cause of your headache i guess.
If you need many to many relation between them,then you should not put this property inside your Task Class
public Person CreatedById { get; set; }
public Person CreatedBy { get; set; }
Or If you need one to many relation between them,then Remove this property form your Task class
public virtual ICollection<Person> PeopleAssigned { get; set; }
Related
i am designing a system and one of my entity has one to many relation as shown below.
public class Product
{
public int Id { get; set; }
}
public class CompetitorProduct
{
public int Id { get; set; }
public Product Product { get; set; }
}
competitorProduct indicates that product has a equivalent which is sold by different store. should i define one-to-many relation as shown above or below? which one is correct?
public class Product
{
public int Id { get; set; }
public virtual ICollection<CompetitorProduct> CompetitorProducts{ get; set; }
}
public class CompetitorProduct
{
public int Id { get; set; }
}
Assuming it is a one to many relationship (what would happen if a competitor product was competing with more than one of your products for example) you can do both and add in a foreign key as well.
public class Product
{
public int Id { get; set; }
public virtual ICollection<CompetitorProduct> CompetitorProducts { get; set; }
}
public class CompetitorProduct
{
public int Id { get; set; }
public int ProductId { get; set; }
public virtual Product Product { get; set; }
}
You can then set up your relationship using fluent API as so:
modelBuilder.Entity<CompetitorProduct>(entity =>
{
entity.HasOne(e => e.Product)
.WithMany(e => e.CompetitorProducts)
.HasForeignKey(e => e.ProductId)
.HasConstraintName("FK_ComptetitorProduct_Product");
});
This way you can access the competitor products from the product and the product from the competitor products.
Here is a quick example of a ecommerce site I have worked on and how we did table relations.
I removed a bunch of the fields so you can see what you really need. Once to make relations and run Add-Migration EF will handle the FK constraints for you as long as you identified them in models like how I have below.
public class ApplicationUser : IdentityUser
{
public ApplicationUser()
{
Active = true;
CreateDateTimeUtc = DateTime.UtcNow;
ModifiedDateTimeUtc = DateTime.UtcNow;
}
[StringLength(500)]
public string FirstName { get; set; }
[StringLength(500)]
public string LastName { get; set; }
[StringLength(1000)]
public string Address { get; set; }
[StringLength(100)]
public string Unit { get; set; }
[StringLength(250)]
public string City { get; set; }
[StringLength(25)]
public string State { get; set; }
[StringLength(20)]
public string ZipCode { get; set; }
//This will give access to a list of child carts a user could have
[Index]
public bool Active { get; set; }
public virtual ICollection<Cart> Carts { get; set; }
// Account Profile Image
public byte[] ProfileImage { get; set; }
[StringLength(500)]
public string ProfileFilename { get; set; }
[StringLength(100)]
public string ProfileMimeType { get; set; }
}
[Table("Cart", Schema = "dbo")]
public class Cart : AbstractTable
{
public Cart()
{
IsComplete = false;
}
//This create relation to user table where I can get one unique user.
[StringLength(128)]
[ForeignKey("ApplicationUser")]
public string UserId { get; set; }
public virtual ApplicationUser ApplicationUser { get; set; }
//These link us to child tables of Cart where we can get a LIST of the items below
public virtual ICollection<CartCategory> CartCategories { get; set; }
public virtual ICollection<CartItem> CartItems { get; set; }
// Marked when a payment/receipt is generated based off of this cart
public bool IsComplete { get; set; }
}
[Table("CartItem", Schema = "dbo")]
public class CartItem : AbstractTable
{
//This will return one unique cart id and let us access it as the parent record
[ForeignKey("Cart")]
public Guid CartId { get; set; }
public virtual Cart Cart { get; set; }
// Signifies if this was paid for in a receipt
public bool IsComplete { get; set; }
public virtual ICollection<CartItemCustomField> CustomFields { get; set; }
}
My data class is
public class Data
{
public int Id { get; set; }
public int LeagueId { get; set; }
public League League { get; set; }
public int HomeTeamId { get; set; }
public virtual Team HomeTeam { get; set; }
public int AwayTeamId { get; set; }
public virtual Team AwayTeam { get; set; }
}
and my team class is
public class Team
{
public int Id { get; set; }
public string Name { get; set; }
public virtual ICollection<Data> Datas { get; set; }
}
which generates an extra foreign key FK_dbo.Data_dbo.Teams_Team_Id and also and extra column in my Data table.
So my first question is, how that foreign-key was created there?
Can i have two one to many relationships that target at the same table with entity framework?
I need to set both the HomeTeamId and the AwayTeamId in the Data table as one to many relationship
Try:
public class Data
{
public int Id { get; set; }
public int LeagueId { get; set; }
[ForeignKey("LeagueId")] /* Add explicit foreign key data annotations */
public League League { get; set; }
public int HomeTeamId { get; set; }
[ForeignKey("HomeTeamId")]
public virtual Team HomeTeam { get; set; }
public int AwayTeamId { get; set; }
[ForeignKey("AwayTeamId")]
public virtual Team AwayTeam { get; set; }
}
public class Team
{
public Team()
{
this.HomeTeamData = new HashSet<Data>();
this.AwayTeamData = new HashSet<Data>();
}
public int Id { get; set; }
public string Name { get; set; }
[InverseProperty("HomeTeam")]
public virtual ICollection<Data> HomeTeamData { get; set; }
[InverseProperty("AwayTeam")]
public virtual ICollection<Data> AwayTeamData { get; set; }
}
Let me know if this helps.
I suspect you may be hitting the limit of Entity's ability to figure out what you want. You may need to consider using some Entity Annotations to instruct Entity on what you want it to actually do.
I am trying to update an record in my system. Everything on the model saves great, except any of my many to many type relationships on the form. When I get to those in my model it gives me the error. "The member with identity 'PmData.SafetyRequirement_Assets' does not exist in the metadata collection.\r\nParameter name: identity". I've read over some of the other answers but I do not have any triggers on my database, and I've gone through several changes in my model based on other suggestions and it doesn't seem to change anything. The project is in vNext.
Here is my first model
public partial class Asset : DataModel
{
[Required]
[StringLength(64)]
public string Name { get; set; }
[StringLength(256)]
public string Description { get; set; }
[StringLength(1024)]
public string SystemFunction { get; set; }
[StringLength(2048)]
public string Remarks { get; set; }
public bool IsSystem { get; set; }
public bool IsGrouping { get; set; }
[StringLength(128)]
public string FieldTag { get; set; }
[ForeignKey("Parent")]
public int? ParentId { get; set; }
[ForeignKey("Building")]
public int? BuildingId { get; set; }
public bool IsOperable { get; set; }
public bool IsAvailable { get; set; }
public virtual Asset Parent { get; set; }
public virtual Building Building { get; set; }
public virtual ICollection<Asset> Children { get; set; }
public virtual ICollection<DrawingReference> DrawingReferences { get; set; }
public virtual ICollection<SpecReference> SpecReferences { get; set; }
public virtual ICollection<SafetyRequirement> SafetyRequirements { get; set; }
public virtual ICollection<SupportSystem> SupportSystems { get; set; }
}
The model for one the other table with a many to many.
public partial class SafetyRequirement : DataModel
{
[StringLength(256)]
[Required]
public string Name { get; set; }
[StringLength(2048)]
public string SafetyFunction { get; set; }
[StringLength(2048)]
public string FunctionalRequirements { get; set; }
[StringLength(2048)]
public string SystemBoundary { get; set; }
[StringLength(255)]
public string Reference { get; set; }
[ForeignKey("QualityLevel")]
public int QualityLevelId { get; set; }
public virtual QualityLevel QualityLevel { get; set; }
public virtual ICollection<Asset> Assets { get; set; }
}
The map for the joining table
modelBuilder.Entity<Asset>().HasMany(t => t.SafetyRequirements)
.WithMany(t => t.Assets)
.Map(m =>
{
m.MapRightKey("SafetyRequirementId");
m.MapLeftKey("AssetId");
m.ToTable("AssetSafetyRequirement");
});
Finally here's the area that it fails...
public virtual void SaveAsync(TEntity model)
{
Task.Run(() =>
{
using (
var dbContext =
(TContext)
Activator.CreateInstance(typeof (TContext),
ConfigOptions == null ? ConfigService.ConnectionString : ConfigOptions.ConnectionString))
{
var dbSet = dbContext.Set<TEntity>();
dbSet.Attach(model);
dbContext.Entry(model).State = EntityState.Modified;
dbContext.SaveChanges();
}
});
}
Any information or pointers would be greatly appreciated.
You're trying to use both Fluent API and Data Annotations to define the relationships between your tables. Remove one or the other.
I am a VB.NET programmer, but I am trying to learn C# and MVC in my spare time. I am using ASP.NET MVC 5.1.0.0 and I am trying to do code-First database creation in a local instance of SQL Server.
I was able to get the first database table to update in the database when I ran Update-Database from within the IDE, but when I added a second table that has a PK/FK relationship with the first, I am getting a red line under [ForeignKey] which reads
Does not contain a constructor that takes 1 arguments
I have been searching all over and not getting anywhere. Any suggestions or help would be appreciated. By the way, the first table is a PK/FK relationship to the AspNetUsers table.
public class BuildDatabase : IdentityUser
{
public virtual Companies Companies { get; set; }
public virtual NotaryProfile NotaryProfile { get; set; }
}
public class Companies
{
[Key]
[Column("CompanyID")] // Did this as the database will reflect TableName_ColumnName instead.
public int CompanyID { get; set; }
public string CompanyName { get; set; }
public bool IsActive { get; set; }
public bool IsNotary { get; set; }
public virtual ICollection<NotaryProfile> NotaryProfile { get; set; }
}
public class NotaryProfile
{
[Key]
public int NotaryID { get; set; }
public string NamePrefix { get; set; }
public string FirstName { get; set; }
public string MiddleInitial { get; set; }
public string LastName { get; set; }
public string NameSuffix { get; set; }
public bool IsActive { get; set; }
public int DefaultState { get; set; }
public int DefaultCounty { get; set; }
public bool IsSigningAgent { get; set; }
public bool HasABond { get; set; }
public decimal BondAmount { get; set; }
public bool HasEandO { get; set; }
public decimal EandOAmount { get; set; }
public bool ElectronicNotarizationsAllowed { get; set; }
public string ElectronicTechnologyUsed { get; set; }
public string ComissionNumber { get; set; }
public DateTime CommissionIssued { get; set; }
public DateTime CommssionOriginal { get; set; }
public DateTime CommissionExpires { get; set; }
public DateTime CommissionFiledOn { get; set; }
public string SOSAuditNumber { get; set; }
public string CommissionDesc { get; set; }
[Foreignkey("CompanyID")] // Companies.CompanyID = PK
public int CompanyID { get; set; } // PK/FK relationship.
public Companies Companies { get; set; } // Reference to Companies table above.
}
public class SchemaDBContext : IdentityDbContext<BuildDatabase>
{
public SchemaDBContext()
: base("DefaultConnection"){}
public DbSet<Companies> Companies { get; set; }
public DbSet<NotaryProfile> NotaryProfile { get; set; }
}
One of your classes (probably NotaryProfile) needs to reference another object (the foreign key relationship) but there is no constructor in that class that accepts an argument to establish that relationship, e.g.:
public NotaryProfile(int companyId) {
this.companyId = companyId;
}
BTW, a better way to establish that relationship is to use the actual class type rather than the ID, as in:
public class NotaryProfile {
...
public Company Company { get; set; }
// Instead of this:
// public int CompanyID { get; set; } // PK/FK relationship.
...
}
See also:
C# “does not contain a constructor that takes '1' arguments”
Does not contain a constructor that takes 2 arguments
Hello had this problem before with another data type. For more details you can see here.
Multiplicity constraint violated Entity framework 5
But now that solution doesn't work or any other found on the net.
My classes are:
namespace Prometheus.Models
{
[Table("People")]
public class Person : IPerson, INamedEntity
{
[Key]
[DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
public virtual int Id { get; set; }
[DisplayName("Prenume")]
public virtual string FirstName { get; set; }
[DisplayName("Nume")]
public virtual string LastName { get; set; }
public string Name
{
get
{
return FirstName + " " + LastName;
}
set { }
}
[DisplayName("Email")]
public virtual string Email { get; set; }
public DateTime? LastModified { get; set; }
public virtual ICollection<Result> Results { get; set; }
public virtual ICollection<Project> Projects { get; set; }
}
}
And
public class Project :INamedEntity
{
public int Id { get; set; }
public DateTime? LastModified { get; set; }
[DisplayName("Titlu Proiect")]
[Required]
public string Name { get; set; }//Title
[Required]
[DisplayName("Tip proiect")]
public virtual ProjectType ProjectType{ get; set; }
[DisplayName("Status proiect")]
public virtual ProjectStatus ProjectStatus { get; set; }
[Required]
[DisplayName("Tip program")]
public virtual ProgramType ProgramType { get; set; }
[Required]
[DisplayName("Numar luni")]
public int NumberOfMonths { get; set; }
[Required]
[DisplayName("Project title")]
public string NameEn { get; set; }
[Required]
[DisplayName("Acronim")]
public string Acronym { get; set; }
[Required]
[DisplayName("Numar contract")]
public string ContractNo { get; set; }
[Required]
[DisplayName("Domeniu de activitate")]
public virtual ActivityField ActivityField {get;set;}
[Required]
[DisplayName("Summary")]
public string SummaryEn { get; set; }
[Required]
[DisplayName("Rezumat")]
public string SumarryRo { get; set; }
[Required]
[DisplayName("Data inceput")]
public virtual DateTime StartDate { get; set; }
[Required]
[DisplayName("Data sfarsit")]
public virtual DateTime EndDate { get; set; }
[Required]
[DisplayName("Institutie coordonatoare")]
public virtual string CoordInstitution { get; set; }
[DisplayName("Valoare totala proiect")]
public decimal TotalValue { get; set; }
[DisplayName("Valuta")]
public virtual Currency Currency { get; set; }
[DisplayName("Rol in proiect")]
public virtual RoleInProject RoleInProject { get; set; }//coord proiect/partener/in afara inst
[DisplayName("Echipa proiect")]
public virtual ICollection<Person> People { get; set; }
[DisplayName("Director proiect")]
public virtual Person ProjectManager { get; set; }
public virtual ICollection<Institution> Partners { get;set;}
public virtual Person PersonInCharge { get; set; }
[DisplayName("Functie/Rol Expert In Proiect")]
public string UserFunctionInProject { get; set; }
[DisplayName("Pagina proiectului")]
[Required]
public string Website {get;set;}
public virtual ICollection<Result> Results { get; set; }
}
When i had the previous problem it was with a class Result and the same Person and was told that if i want a many-to-many relationship i have to add a Collection to Person and a Collection to Result and that did the trick.
But now as you can see i already have
public virtual ICollection<Person> People { get; set; } in Project
and
public virtual ICollection<Project> Projects { get; set; } in Person
And every time i try to add more than one User to the project i get the error in that title when calling the Save() method from DbContext
I have no idea what to do.
Thanks.
Accidentally posted the wrong class, it was the result instead of the Person, now it's correct
Update 1
public void AddProjectForUsers(IEnumerable<int> userIds, Project project)
{
foreach (var id in userIds)
{
AddProjectForUser(id,project);
}
}
public void AddProjectForUser(int userId, Project project)
{
var user = _ctx.Users.SingleOrDefault(u => u.Id == userId);
if (user != null)
{
if (!user.Projects.Contains(project))
{
user.Projects.Add(project);
}
}
}
public bool Save()
{
return _ctx.SaveChanges() > 0; // the error is thrown here
}
The 3 are from my repository class
And the call to them is
Repo.AddProjectForUsers(team, project);
Repo.Save();
Where team is an IEnumerable<int> and project is of type Project
It looks like you may need the InverseProperty data annotation attribute to do this:
namespace Prometheus.Models
{
[Table("People")]
public class Person : IPerson, INamedEntity
{
...
[InverseProperty("People")]
public virtual ICollection<Project> Projects { get; set; }
}
}
public class Project :INamedEntity
{
...
[DisplayName("Echipa proiect")]
[InverseProperty("Projects")]
public virtual ICollection<Person> People { get; set; }
}
The exception message you are receiving is very telling. Since EF is complaining that the relation is expected to be a one-to-zero-or-one, this leads me to believe that EF is confusing the People - Projects association with either the PersonInCharge - Project or ProjectManager - Project association.
One way to solve this would be to expose foreign key properties on your Project entity, which you should be doing anyway - you can get weird transient errors when you don't. Another way would be to use the fluent API (a.k.a. model builder) instead of data annotations.