I have two entities Employer and Address
public class Employer
{
public int Code { get; set; }
public string Initials { get; set; }
public string Description { get; set; }
public virtual Address Address { get; private set; }
}
public class Address
{
public string Email { get; private set; }
public string City { get; private set; }
public string PostalCode { get; private set; }
public string AddressLine { get; private set; }
}
I have a method to track changes on both entities for audit purposes. I would like to track the changes on the owned type but I get
"System.InvalidOperationException: 'The property 'Address' on entity type 'Employer' is being accessed using the 'Property' method, but is defined in the model as a navigation property. Use either the 'Reference' or 'Collection' method to access navigation properties.'"
Any idea on how I can fix this?
Related
I am trying to make a simple website that tracks students, programs, and classes. I've created the entities and I'm getting an error when trying to add the migration.
"The entity type 'Program' requires a primary key to be defined."
I have tried using the [Key] attribute and there is an Id field. The other table was created just fine. What else should I try?
Here is the problem class:
public class Program
{
public int Id { get; set; }
public string Name { get; set; }
public string Description { get; set; }
public bool UseRanks { get; set; }
}
Here is another table that I had no problems creating a migration for:
public class Person
{
public int Id { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public string CellPhone { get; set; }
public string HomePhone { get; set; }
public string WorkPhone { get; set; }
public string Address { get; set; }
public string City { get; set; }
public string State { get; set; }
public string ZipCode { get; set; }
public DateTime BirthDate { get; set; }
}
Here is what is in my ApplicationDbContext class:
public class ApplicationDbContext : IdentityDbContext
{
public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options)
: base(options)
{
}
//public DbSet<Attendance> Attendances { get; set; }
public DbSet<Person> People { get; set; }
public DbSet<Bill> Bills { get; set; }
//public DbSet<Session> Sessions { get; set; }
public DbSet<Program> Programs { get; set; }
}
I've commented out the other entities because I was trying to add them one at a time. Trying to add a migration with all the entities resulted in the same error with the same specific class.
Complete shot in the dark, but based on the name of this class, I'm guessing you're referencing the wrong Program. Make sure that your DbSet<Program> is actually using your Program entity and not something like the Program class used at the console app level. You'll likely need to explicitly use the namespace, i.e. DbSet<MyApp.Models.Program>.
You might also consider changing the name of the class to remove any chance of ambiguity. There's some class names that are just going to wreck havoc trying to use them because they'll conflict with framework stuff constantly. It's usually more hassle than it's worth just to have that particular name. Program is one of those.
You can try to use this way:
public class Program
{
[Key]
public int Id { get; set; }
public string Name { get; set; }
public string Description { get; set; }
public bool UseRanks { get; set; }
}
Adding [Key] attribute to the Id property.
In the file ApplicationDbContext.cs, you can override OnModelCreating method:
public DbSet<Program> Programs { get; set; }
protected override void OnModelCreating(ModelBuilder builder)
{
base.OnModelCreating(builder);
builder.Entity<Program>().ToTable("Programs").HasKey(x => x.Id);
}
Model:
public class Address
{
[Key]
public long AddressId { get; set; }
public string Street { get; set; }
public string Town { get; set; }
public string State { get; set; }
public string Country { get; set; }
}
public class User
{
[Key]
public long UserId { get; set; }
public string UserName { get; set; }
public string Password { get; set; }
public virtual List<Address> Addresses { get; set; }
}
DBContext:
public class DataModelContext : DbContext
{
public DbSet<Address> Addresses { get; set; }
public DbSet<User> Users{ get; set; }
}
Using above code its creating this schema for DB.
Addresses Users
----------- -------
AddressId(PK) UserId(PK)
Street UserName
Town Password
State
Country
User_UserId(FK)
Now i want to access User_UserId from Addresses table, but it not showing any property there. Its giving error "Address does not contain a definition for User_UserId.....
using (var db = new DataModelContext())
{
db.Addresses.Select(x=>x.User_UserId).ToList();
}
Use Foreign-Key Association instead of independant association while creating models. It means that, you must include a foreign key property in your model alongside with a corresponding Navigational Property. For example:
public class Address
{
...
public int UserId {get; set;} //Foreign-Key property
[ForeignKey("UserId")]
public virtual User User { get; set; } // Navigational Property
...
}
Read this article for more information.
My user looks like this:
public class User
{
public User()
{
Subscribers = new List<SubscriberNumber>();
}
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int UserId { get; set; }
public string Username { get; set; }
[Required]
public virtual BusinessNumber BusinessNumber { get; set; }
public string BusinessName { get; set; }
public int SubscriberCount { get; set; }
public List<SubscriberNumber> Subscribers { get; set; }
}
The following call fails due to some undisclosed EntityValidationError:
var user = db.Users.First(s => s.Username == username);
user.BusinessName = "test";
db.SaveChanges();
But either opening up user.BusinessNumber in VS or using the following:
var user = db.Users.Include(s => s.BusinessNumber).First(s => s.Username == username);
gets SaveChanges() to work. Do I always have to include virtual properties when I'm updating my Users? This seems cumbersome...
The virtual on the properties allows EF to build a proxy. It is not essential to use virtual on regular properties for EF to read and write data. However Virtual is required on the Navigation properties.
By Default Context.Configuration.ValidateOnSaveEnabled = true;
EF will trigger validation on SaveChanges().
So in teh example where the Navigation property is Required (why?) The you must first populate it in the context and POCO. Placing the [required] on the foreign key property rather than the navigation property would be more common.
public class User
{
public User()
{
Subscribers = new List<SubscriberNumber>();
}
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int UserId { get; set; }
public string Username { get; set; }
[Required]
public virtual int BusinessId {get;set;}; // make the foreign key to BusinessNumber required if necessary
[ForeignKey("BusinessId")]
public virtual BusinessNumber BusinessNumber { get; set; } // this is a nav prop, since it isnt a simple base type
public string BusinessName { get; set; }
public int SubscriberCount { get; set; }
public List<SubscriberNumber> Subscribers { get; set; }
}
I am getting this error in my .Net MVC 4 web application:
The property 'Username' cannot be configured as a navigation property. The
property must be a valid entity type and the property should have a non-abstract
getter and setter. For collection properties the type must implement
ICollection<T> where T is a valid entity type.
I am very new to Entity Framework and I can't seem to get around this issue. Here is some code:
//DB Context
public class EFDbContext : DbContext
{
public DbSet<User> Users { get; set; }
public DbSet<Role> Roles { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<User>().HasMany(u => u.Roles).WithMany(r => r.Users).Map(x => x.MapLeftKey("Username").MapRightKey("RoleName").ToTable("Users_Roles"));
}
}
//Entity Classes
public class User
{
[Key]
public string Username { get; set; }
public string Password { get; set; }
public string Email { get; set; }
public string Comment { get; set; }
public int Level { get; set; }
public string PasswordQuestion { get; set; }
public string PasswordAnswer { get; set; }
public bool IsApproved { get; set; }
public DateTime LastActivityDate { get; set; }
public DateTime LastLoginDate { get; set; }
public DateTime LastPasswordChangedDate { get; set; }
public DateTime CreationDate { get; set; }
public bool IsOnLine { get; set; }
public bool IsLockedOut { get; set; }
public DateTime LastLockedOutDate { get; set; }
public int FailedPasswordAttemptCount { get; set; }
public DateTime FailedPasswordAttemptWindowStart { get; set; }
public int FailedPasswordAnswerAttemptCount { get; set; }
public DateTime FailedPasswordAnswerAttemptWindowStart { get; set; }
[InverseProperty("RoleName")]
public virtual ICollection<Role> Roles { get; set; }
public override string ToString()
{
return this.Username;
}
}
public class Role
{
[Key]
public string RoleName { get; set; }
public int Level { get; set; }
[InverseProperty("Username")]
public virtual ICollection<User> Users { get; set; }
public override string ToString()
{
return this.RoleName;
}
}
//Repository
public class EFUsersRepository : IUsersRepository
{
private EFDbContext context = new EFDbContext();
public IQueryable<User> Users
{
get { return context.Users; }
}
public User GetUser(string username)
{
return context.Users.Find(username); //THIS IS WHERE THE CRASH OCCURS
}
}
//DB Setup
Table Users, Role and Users_Role. Users_Role is a simple linking table with [username, role] columns both of type varchar.
The database tables columns & types match the two classes above (User,Role).
I inherited this project which was unfinished but I can't get it to run successfully. Any help understanding what the issue is would be helpful. Thanks!
It might be that Entity Framework is updated. Easiest way will be to recreate the DataModel.
Even if the previous programmer did not use Entity Data Mode, you can at least copy the auto generated code such as EFDbContext, Users and Roles classes.
It turns out, after commenting out enough items all day long, the the following lines are what caused this error for me:
[InverseProperty("RoleName")] //In file User.cs (as shown above)
[InverseProperty("UserName")] //in file Role.cs (as shown above)
I am still learning Entity Framework and I don't know why this was the solution, but it stopped the error which I reported above.
I hope that this helps someone else and if anyone wants to help me understand what the issue was in detail, please feel free. I am eager to learn.
I recently came across this strange problem with Entity Framework Code First.
My class looks like this
public class Status
{
[Key]
public int StatusID { get; set; }
public string Name { get; set; }
public int MemberID { get; set; }
[ForeignKey("MemberID")]
public virtual Member Member { get; set; }
public int PosterID { get; set; }
[ForeignKey("PosterID")]
public virtual Member Poster { get; set; }
public virtual ICollection<StatusLike> StatusLikes { get; set; }
public virtual ICollection<StatusComment> StatusComments { get; set; }
}
My Member class looks like this
public class Member
{
[Key]
public int MemberID { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public string Bio { get; set; }
public virtual ICollection<MemberCourseTaken> MemberCourseTakens { get; set; }
public virtual ICollection<Status> Statuses { get; set; }
public virtual ICollection<Club> FoundedClubs { get; set; }
public string EmailAddress { get; set; }
public string Password { get; set; }
public string Phone { get; set; }
public int AccountSourceID { get; set; }
public AccountSource AccountSource { get; set; }
public int AddressID { get; set; }
public Address Address { get; set; }
public string ProfilePhoto { get; set; }
public int MemberRankID { get; set; }
public MemberRank MemberRank { get; set; }
public DateTime Created { get; set; }
public DateTime Modified { get; set; }
}
And for whatever reason the database table that is created has the following columns
StatusID
Name
MemberID
PosterID
Member_MemberID
with MemberID, PosterID, and Member_MemberID being foreign keys.
How can I keep Member_MemberID from being generated?
Your Member_MemberID column is created because of the Member.Statuses property. I can imagine that this is not what you want. Probably members and statuses should exist independent of each other, so you need a junction table.
I don't know if you already use the OnModelCreating override of the DbContext, but that's the place to change the mapping between Member and Status:
protected override void OnModelCreating(DbModelBuilder mb)
{
mb.Entity<Member>().HasMany(m => m.Statuses).WithMany();
}
This will create a table MemberStatuses table with the two Id columns as foreign keys. This is a way to model a many-to-many relationship without a navigation property on the "other" side of the association. (I don't think you want a Members property in Status).
I've seen this before. In my case (Using EF 6.1), it was because my Fluent API Mapping was set up like so:
// In my EntityTypeConfiguration<Status>
HasRequired(x => x.Member).WithMany().HasForeignKey(x => x.MemberID);
That code works perfectly fine, but it doesn't tell EF that my Member class's Collection Navigational Property Status ha been taken into account. So, while I explicitly handled the existence of a Member Navigational Property in my Status Class, I now left an orphaned related collection property. That orphaned property, being a collection, tells EF that my Status class needs to have a Foreign Key to it. So it creates that on the Status Class.
To fix it, I had to be 100% explicit.
HasRequired(x => x.Member).WithMany(x => x.Statuses).HasForeignKey(x => x.MemberID)
It could bee that your Statuses Collection property in Member needs an attribute telling it that it is already considered, and not to go auto-creating mappings. I don't know that attribute.