外键关系EF代码优先

Question

I'm busy creating my first EF code first model and I've come across a slightly confusing problem.

I have a number of model classes that each inherit from a base model class that has three common properties I want used in all model classes. These properties are Id, LastUpdated and LastUpdatedBy.

Id is the primary key of each model class. LastUpdated is a foreign key to my 'User' model class. LastUpdatedBy is a datetime field that indicates the last time the record was modified.

So what I'd like to setup is the 1 to 1 foreign key relationship from my base class to my 'User' model class but I'm receiving the exception:

Multiplicity is not valid in Role 'Profile_LastUpdatedByUser_Source' in relationship 'Profile_LastUpdatedByUser'. Because the Dependent Role properties are not the key properties, the upper bound of the multiplicity of the Dependent Role must be '*'

This is my ModelBase class:

public class ModelBase
    {
        public int Id { get; set; }
        public DateTime LastUpdated { get; set; }

        [ForeignKey("LastUpdatedByUser")]
        [Required]
        public int LastUpdatedByUserId { get; set; }

        public virtual User LastUpdatedByUser { get; set; }
    }

This is one of my model classes:

public class Profile : ModelBase
    {
        [StringLength(25, MinimumLength=1)]
        [Required(ErrorMessage="First Name is Required")]
        public string FirstName { get; set; }

        [StringLength(25, MinimumLength = 1)]
        [Required(ErrorMessage = "Last Name is Required")]
        public string LastName { get; set; }

        [StringLength(25, MinimumLength = 1)]
        [Required(ErrorMessage = "Email Address is Required")]
        public string Email { get; set; }

        public string Mobile { get; set; }
        public string HomePhone { get; set; }
        public string WorkPhone { get; set; }

        public string ImageSource { get; set; }

        public Squable.Model.Enums.MembershipType.MembershipTypeEnum MembershipType { get; set; }
    }

This is my user class (Please ignore the Password property, I'll fix that later ;) ):

public class User : ModelBase
    {
        public string UserName { get; set; }
        public string Password { get; set; }

        public int ProfileId { get; set; }
        public virtual Profile Profile { get; set; }
    }

I don't know if what I am doing is best practise but I could do with some advice as to how to either fix the problem or maybe just some pointers in the right direction.

Answer 1

Move

public int Id { get; set; }

to User class and to Profile you can also change the names to UserId and to ProfileId and move

public virtual User LastUpdatedByUser { get; set; }

to Profile class.

I have a bad experience with sharing Id in base entity If you are planning to use Repository and UnitOfWork pattern you will get a lot of problems later. Check your current database structure and tables with SQL Server Management Studio.

More Info TPH